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cos(t)≤-√2/2 inequation

A inequation with variable

The solution

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             ___ 
          -\/ 2  
cos(t) <= -------
             2   
cos(t)(1)22\cos{\left(t \right)} \leq \frac{\left(-1\right) \sqrt{2}}{2}
cos(t) <= (-sqrt(2))/2
Detail solution
Given the inequality:
cos(t)(1)22\cos{\left(t \right)} \leq \frac{\left(-1\right) \sqrt{2}}{2}
To solve this inequality, we must first solve the corresponding equation:
cos(t)=(1)22\cos{\left(t \right)} = \frac{\left(-1\right) \sqrt{2}}{2}
Solve:
x1=79.3252145031423x_{1} = -79.3252145031423
x2=66.7588438887831x_{2} = -66.7588438887831
x3=73.0420291959627x_{3} = -73.0420291959627
x4=85.6083998103219x_{4} = -85.6083998103219
x5=21.2057504117311x_{5} = -21.2057504117311
x6=10.2101761241668x_{6} = -10.2101761241668
x7=335.36501577071x_{7} = -335.36501577071
x8=41.6261026600648x_{8} = 41.6261026600648
x9=29.0597320457056x_{9} = -29.0597320457056
x10=90.3207887907066x_{10} = 90.3207887907066
x11=35.3429173528852x_{11} = -35.3429173528852
x12=21.2057504117311x_{12} = 21.2057504117311
x13=2.35619449019234x_{13} = 2.35619449019234
x14=8.63937979737193x_{14} = 8.63937979737193
x15=60.4756585816035x_{15} = -60.4756585816035
x16=52.621676947629x_{16} = -52.621676947629
x17=255.254403104171x_{17} = 255.254403104171
x18=79.3252145031423x_{18} = 79.3252145031423
x19=3.92699081698724x_{19} = 3.92699081698724
x20=35.3429173528852x_{20} = 35.3429173528852
x21=46.3384916404494x_{21} = -46.3384916404494
x22=60.4756585816035x_{22} = 60.4756585816035
x23=27.4889357189107x_{23} = -27.4889357189107
x24=2.35619449019234x_{24} = -2.35619449019234
x25=29.0597320457056x_{25} = 29.0597320457056
x26=71.4712328691678x_{26} = 71.4712328691678
x27=90.3207887907066x_{27} = -90.3207887907066
x28=39349.2333843756x_{28} = 39349.2333843756
x29=14.9225651045515x_{29} = 14.9225651045515
x30=47.9092879672443x_{30} = 47.9092879672443
x31=77.7544181763474x_{31} = -77.7544181763474
x32=33.7721210260903x_{32} = 33.7721210260903
x33=73.0420291959627x_{33} = 73.0420291959627
x34=77.7544181763474x_{34} = 77.7544181763474
x35=54.1924732744239x_{35} = -54.1924732744239
x36=54.1924732744239x_{36} = 54.1924732744239
x37=46.3384916404494x_{37} = 46.3384916404494
x38=47.9092879672443x_{38} = -47.9092879672443
x39=65.1880475619882x_{39} = -65.1880475619882
x40=2584.745355741x_{40} = 2584.745355741
x41=96.6039740978861x_{41} = 96.6039740978861
x42=66.7588438887831x_{42} = 66.7588438887831
x43=96.6039740978861x_{43} = -96.6039740978861
x44=65.1880475619882x_{44} = 65.1880475619882
x45=104.457955731861x_{45} = 104.457955731861
x46=85.6083998103219x_{46} = 85.6083998103219
x47=16.4933614313464x_{47} = 16.4933614313464
x48=71.4712328691678x_{48} = -71.4712328691678
x49=8.63937979737193x_{49} = -8.63937979737193
x50=3.92699081698724x_{50} = -3.92699081698724
x51=27.4889357189107x_{51} = 27.4889357189107
x52=98.174770424681x_{52} = 98.174770424681
x53=52.621676947629x_{53} = 52.621676947629
x54=14.9225651045515x_{54} = -14.9225651045515
x55=40.0553063332699x_{55} = -40.0553063332699
x56=22.776546738526x_{56} = 22.776546738526
x57=41.6261026600648x_{57} = -41.6261026600648
x58=16.4933614313464x_{58} = -16.4933614313464
x59=40.0553063332699x_{59} = 40.0553063332699
x60=58.9048622548086x_{60} = 58.9048622548086
x61=58.9048622548086x_{61} = -58.9048622548086
x62=84.037603483527x_{62} = -84.037603483527
x63=91.8915851175014x_{63} = 91.8915851175014
x64=33.7721210260903x_{64} = -33.7721210260903
x65=10.2101761241668x_{65} = 10.2101761241668
x66=22.776546738526x_{66} = -22.776546738526
x67=98.174770424681x_{67} = -98.174770424681
x68=84.037603483527x_{68} = 84.037603483527
x69=91.8915851175014x_{69} = -91.8915851175014
x1=79.3252145031423x_{1} = -79.3252145031423
x2=66.7588438887831x_{2} = -66.7588438887831
x3=73.0420291959627x_{3} = -73.0420291959627
x4=85.6083998103219x_{4} = -85.6083998103219
x5=21.2057504117311x_{5} = -21.2057504117311
x6=10.2101761241668x_{6} = -10.2101761241668
x7=335.36501577071x_{7} = -335.36501577071
x8=41.6261026600648x_{8} = 41.6261026600648
x9=29.0597320457056x_{9} = -29.0597320457056
x10=90.3207887907066x_{10} = 90.3207887907066
x11=35.3429173528852x_{11} = -35.3429173528852
x12=21.2057504117311x_{12} = 21.2057504117311
x13=2.35619449019234x_{13} = 2.35619449019234
x14=8.63937979737193x_{14} = 8.63937979737193
x15=60.4756585816035x_{15} = -60.4756585816035
x16=52.621676947629x_{16} = -52.621676947629
x17=255.254403104171x_{17} = 255.254403104171
x18=79.3252145031423x_{18} = 79.3252145031423
x19=3.92699081698724x_{19} = 3.92699081698724
x20=35.3429173528852x_{20} = 35.3429173528852
x21=46.3384916404494x_{21} = -46.3384916404494
x22=60.4756585816035x_{22} = 60.4756585816035
x23=27.4889357189107x_{23} = -27.4889357189107
x24=2.35619449019234x_{24} = -2.35619449019234
x25=29.0597320457056x_{25} = 29.0597320457056
x26=71.4712328691678x_{26} = 71.4712328691678
x27=90.3207887907066x_{27} = -90.3207887907066
x28=39349.2333843756x_{28} = 39349.2333843756
x29=14.9225651045515x_{29} = 14.9225651045515
x30=47.9092879672443x_{30} = 47.9092879672443
x31=77.7544181763474x_{31} = -77.7544181763474
x32=33.7721210260903x_{32} = 33.7721210260903
x33=73.0420291959627x_{33} = 73.0420291959627
x34=77.7544181763474x_{34} = 77.7544181763474
x35=54.1924732744239x_{35} = -54.1924732744239
x36=54.1924732744239x_{36} = 54.1924732744239
x37=46.3384916404494x_{37} = 46.3384916404494
x38=47.9092879672443x_{38} = -47.9092879672443
x39=65.1880475619882x_{39} = -65.1880475619882
x40=2584.745355741x_{40} = 2584.745355741
x41=96.6039740978861x_{41} = 96.6039740978861
x42=66.7588438887831x_{42} = 66.7588438887831
x43=96.6039740978861x_{43} = -96.6039740978861
x44=65.1880475619882x_{44} = 65.1880475619882
x45=104.457955731861x_{45} = 104.457955731861
x46=85.6083998103219x_{46} = 85.6083998103219
x47=16.4933614313464x_{47} = 16.4933614313464
x48=71.4712328691678x_{48} = -71.4712328691678
x49=8.63937979737193x_{49} = -8.63937979737193
x50=3.92699081698724x_{50} = -3.92699081698724
x51=27.4889357189107x_{51} = 27.4889357189107
x52=98.174770424681x_{52} = 98.174770424681
x53=52.621676947629x_{53} = 52.621676947629
x54=14.9225651045515x_{54} = -14.9225651045515
x55=40.0553063332699x_{55} = -40.0553063332699
x56=22.776546738526x_{56} = 22.776546738526
x57=41.6261026600648x_{57} = -41.6261026600648
x58=16.4933614313464x_{58} = -16.4933614313464
x59=40.0553063332699x_{59} = 40.0553063332699
x60=58.9048622548086x_{60} = 58.9048622548086
x61=58.9048622548086x_{61} = -58.9048622548086
x62=84.037603483527x_{62} = -84.037603483527
x63=91.8915851175014x_{63} = 91.8915851175014
x64=33.7721210260903x_{64} = -33.7721210260903
x65=10.2101761241668x_{65} = 10.2101761241668
x66=22.776546738526x_{66} = -22.776546738526
x67=98.174770424681x_{67} = -98.174770424681
x68=84.037603483527x_{68} = 84.037603483527
x69=91.8915851175014x_{69} = -91.8915851175014
This roots
x7=335.36501577071x_{7} = -335.36501577071
x67=98.174770424681x_{67} = -98.174770424681
x43=96.6039740978861x_{43} = -96.6039740978861
x69=91.8915851175014x_{69} = -91.8915851175014
x27=90.3207887907066x_{27} = -90.3207887907066
x4=85.6083998103219x_{4} = -85.6083998103219
x62=84.037603483527x_{62} = -84.037603483527
x1=79.3252145031423x_{1} = -79.3252145031423
x31=77.7544181763474x_{31} = -77.7544181763474
x3=73.0420291959627x_{3} = -73.0420291959627
x48=71.4712328691678x_{48} = -71.4712328691678
x2=66.7588438887831x_{2} = -66.7588438887831
x39=65.1880475619882x_{39} = -65.1880475619882
x15=60.4756585816035x_{15} = -60.4756585816035
x61=58.9048622548086x_{61} = -58.9048622548086
x35=54.1924732744239x_{35} = -54.1924732744239
x16=52.621676947629x_{16} = -52.621676947629
x38=47.9092879672443x_{38} = -47.9092879672443
x21=46.3384916404494x_{21} = -46.3384916404494
x57=41.6261026600648x_{57} = -41.6261026600648
x55=40.0553063332699x_{55} = -40.0553063332699
x11=35.3429173528852x_{11} = -35.3429173528852
x64=33.7721210260903x_{64} = -33.7721210260903
x9=29.0597320457056x_{9} = -29.0597320457056
x23=27.4889357189107x_{23} = -27.4889357189107
x66=22.776546738526x_{66} = -22.776546738526
x5=21.2057504117311x_{5} = -21.2057504117311
x58=16.4933614313464x_{58} = -16.4933614313464
x54=14.9225651045515x_{54} = -14.9225651045515
x6=10.2101761241668x_{6} = -10.2101761241668
x49=8.63937979737193x_{49} = -8.63937979737193
x50=3.92699081698724x_{50} = -3.92699081698724
x24=2.35619449019234x_{24} = -2.35619449019234
x13=2.35619449019234x_{13} = 2.35619449019234
x19=3.92699081698724x_{19} = 3.92699081698724
x14=8.63937979737193x_{14} = 8.63937979737193
x65=10.2101761241668x_{65} = 10.2101761241668
x29=14.9225651045515x_{29} = 14.9225651045515
x47=16.4933614313464x_{47} = 16.4933614313464
x12=21.2057504117311x_{12} = 21.2057504117311
x56=22.776546738526x_{56} = 22.776546738526
x51=27.4889357189107x_{51} = 27.4889357189107
x25=29.0597320457056x_{25} = 29.0597320457056
x32=33.7721210260903x_{32} = 33.7721210260903
x20=35.3429173528852x_{20} = 35.3429173528852
x59=40.0553063332699x_{59} = 40.0553063332699
x8=41.6261026600648x_{8} = 41.6261026600648
x37=46.3384916404494x_{37} = 46.3384916404494
x30=47.9092879672443x_{30} = 47.9092879672443
x53=52.621676947629x_{53} = 52.621676947629
x36=54.1924732744239x_{36} = 54.1924732744239
x60=58.9048622548086x_{60} = 58.9048622548086
x22=60.4756585816035x_{22} = 60.4756585816035
x44=65.1880475619882x_{44} = 65.1880475619882
x42=66.7588438887831x_{42} = 66.7588438887831
x26=71.4712328691678x_{26} = 71.4712328691678
x33=73.0420291959627x_{33} = 73.0420291959627
x34=77.7544181763474x_{34} = 77.7544181763474
x18=79.3252145031423x_{18} = 79.3252145031423
x68=84.037603483527x_{68} = 84.037603483527
x46=85.6083998103219x_{46} = 85.6083998103219
x10=90.3207887907066x_{10} = 90.3207887907066
x63=91.8915851175014x_{63} = 91.8915851175014
x41=96.6039740978861x_{41} = 96.6039740978861
x52=98.174770424681x_{52} = 98.174770424681
x45=104.457955731861x_{45} = 104.457955731861
x17=255.254403104171x_{17} = 255.254403104171
x40=2584.745355741x_{40} = 2584.745355741
x28=39349.2333843756x_{28} = 39349.2333843756
is the points with change the sign of the inequality expression.
First define with the sign to the leftmost point:
x0x7x_{0} \leq x_{7}
For example, let's take the point
x0=x7110x_{0} = x_{7} - \frac{1}{10}
=
335.36501577071+110-335.36501577071 + - \frac{1}{10}
=
335.46501577071-335.46501577071
substitute to the expression
cos(t)(1)22\cos{\left(t \right)} \leq \frac{\left(-1\right) \sqrt{2}}{2}
cos(t)(1)22\cos{\left(t \right)} \leq \frac{\left(-1\right) \sqrt{2}}{2}
             ___ 
          -\/ 2  
cos(t) <= -------
             2   
          

Then
x335.36501577071x \leq -335.36501577071
no execute
one of the solutions of our inequality is:
x335.36501577071x98.174770424681x \geq -335.36501577071 \wedge x \leq -98.174770424681
         _____           _____           _____           _____           _____           _____           _____           _____           _____           _____           _____           _____           _____           _____           _____           _____           _____           _____           _____           _____           _____           _____           _____           _____           _____           _____           _____           _____           _____           _____           _____           _____           _____           _____           _____  
        /     \         /     \         /     \         /     \         /     \         /     \         /     \         /     \         /     \         /     \         /     \         /     \         /     \         /     \         /     \         /     \         /     \         /     \         /     \         /     \         /     \         /     \         /     \         /     \         /     \         /     \         /     \         /     \         /     \         /     \         /     \         /     \         /     \         /     \         /
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       x7      x67      x43      x69      x27      x4      x62      x1      x31      x3      x48      x2      x39      x15      x61      x35      x16      x38      x21      x57      x55      x11      x64      x9      x23      x66      x5      x58      x54      x6      x49      x50      x24      x13      x19      x14      x65      x29      x47      x12      x56      x51      x25      x32      x20      x59      x8      x37      x30      x53      x36      x60      x22      x44      x42      x26      x33      x34      x18      x68      x46      x10      x63      x41      x52      x45      x17      x40      x28

Other solutions will get with the changeover to the next point
etc.
The answer:
x335.36501577071x98.174770424681x \geq -335.36501577071 \wedge x \leq -98.174770424681
x96.6039740978861x91.8915851175014x \geq -96.6039740978861 \wedge x \leq -91.8915851175014
x90.3207887907066x85.6083998103219x \geq -90.3207887907066 \wedge x \leq -85.6083998103219
x84.037603483527x79.3252145031423x \geq -84.037603483527 \wedge x \leq -79.3252145031423
x77.7544181763474x73.0420291959627x \geq -77.7544181763474 \wedge x \leq -73.0420291959627
x71.4712328691678x66.7588438887831x \geq -71.4712328691678 \wedge x \leq -66.7588438887831
x65.1880475619882x60.4756585816035x \geq -65.1880475619882 \wedge x \leq -60.4756585816035
x58.9048622548086x54.1924732744239x \geq -58.9048622548086 \wedge x \leq -54.1924732744239
x52.621676947629x47.9092879672443x \geq -52.621676947629 \wedge x \leq -47.9092879672443
x46.3384916404494x41.6261026600648x \geq -46.3384916404494 \wedge x \leq -41.6261026600648
x40.0553063332699x35.3429173528852x \geq -40.0553063332699 \wedge x \leq -35.3429173528852
x33.7721210260903x29.0597320457056x \geq -33.7721210260903 \wedge x \leq -29.0597320457056
x27.4889357189107x22.776546738526x \geq -27.4889357189107 \wedge x \leq -22.776546738526
x21.2057504117311x16.4933614313464x \geq -21.2057504117311 \wedge x \leq -16.4933614313464
x14.9225651045515x10.2101761241668x \geq -14.9225651045515 \wedge x \leq -10.2101761241668
x8.63937979737193x3.92699081698724x \geq -8.63937979737193 \wedge x \leq -3.92699081698724
x2.35619449019234x2.35619449019234x \geq -2.35619449019234 \wedge x \leq 2.35619449019234
x3.92699081698724x8.63937979737193x \geq 3.92699081698724 \wedge x \leq 8.63937979737193
x10.2101761241668x14.9225651045515x \geq 10.2101761241668 \wedge x \leq 14.9225651045515
x16.4933614313464x21.2057504117311x \geq 16.4933614313464 \wedge x \leq 21.2057504117311
x22.776546738526x27.4889357189107x \geq 22.776546738526 \wedge x \leq 27.4889357189107
x29.0597320457056x33.7721210260903x \geq 29.0597320457056 \wedge x \leq 33.7721210260903
x35.3429173528852x40.0553063332699x \geq 35.3429173528852 \wedge x \leq 40.0553063332699
x41.6261026600648x46.3384916404494x \geq 41.6261026600648 \wedge x \leq 46.3384916404494
x47.9092879672443x52.621676947629x \geq 47.9092879672443 \wedge x \leq 52.621676947629
x54.1924732744239x58.9048622548086x \geq 54.1924732744239 \wedge x \leq 58.9048622548086
x60.4756585816035x65.1880475619882x \geq 60.4756585816035 \wedge x \leq 65.1880475619882
x66.7588438887831x71.4712328691678x \geq 66.7588438887831 \wedge x \leq 71.4712328691678
x73.0420291959627x77.7544181763474x \geq 73.0420291959627 \wedge x \leq 77.7544181763474
x79.3252145031423x84.037603483527x \geq 79.3252145031423 \wedge x \leq 84.037603483527
x85.6083998103219x90.3207887907066x \geq 85.6083998103219 \wedge x \leq 90.3207887907066
x91.8915851175014x96.6039740978861x \geq 91.8915851175014 \wedge x \leq 96.6039740978861
x98.174770424681x104.457955731861x \geq 98.174770424681 \wedge x \leq 104.457955731861
x255.254403104171x2584.745355741x \geq 255.254403104171 \wedge x \leq 2584.745355741
x39349.2333843756x \geq 39349.2333843756
Rapid solution 2 [src]
 3*pi  5*pi 
[----, ----]
  4     4   
x in [3π4,5π4]x\ in\ \left[\frac{3 \pi}{4}, \frac{5 \pi}{4}\right]
x in Interval(3*pi/4, 5*pi/4)
Rapid solution [src]
   /3*pi            5*pi\
And|---- <= x, x <= ----|
   \ 4               4  /
3π4xx5π4\frac{3 \pi}{4} \leq x \wedge x \leq \frac{5 \pi}{4}
(3*pi/4 <= x)∧(x <= 5*pi/4)