Given the inequality:
cos(t)≤21To solve this inequality, we must first solve the corresponding equation:
cos(t)=21Solve:
Given the equation
cos(t)=21transform
cos(t)−21=0cos(t)−21=0Do replacement
w=cos(t)Move free summands (without w)
from left part to right part, we given:
w=21We get the answer: w = 1/2
do backward replacement
cos(t)=wsubstitute w:
x1=38.7463093942741x2=13.6135681655558x3=11.5191730631626x4=−55.5014702134197x5=−30.3687289847013x6=−61.7846555205993x7=−86.9173967493176x8=89.0117918517108x9=−51.3126800086333x10=1.0471975511966x11=−68.0678408277789x12=36.6519142918809x13=−70.162235930172x14=93.2005820564972x15=−95.2949771588904x16=49.2182849062401x17=30.3687289847013x18=17.8023583703422x19=−32.4631240870945x20=−99.4837673636768x21=63.8790506229925x22=42.9350995990605x23=−225.147473507269x24=−93.2005820564972x25=−17.8023583703422x26=7.33038285837618x27=−11.5191730631626x28=57.5958653158129x29=−42.9350995990605x30=−24.0855436775217x31=70.162235930172x32=−36.6519142918809x33=−26.1799387799149x34=19.8967534727354x35=−76.4454212373516x36=76.4454212373516x37=−1.0471975511966x38=1651.43053823704x39=55.5014702134197x40=−5.23598775598299x41=51.3126800086333x42=45.0294947014537x43=68.0678408277789x44=−45.0294947014537x45=−82.7286065445312x46=−19.8967534727354x47=−57.5958653158129x48=74.3510261349584x49=−38.7463093942741x50=80.634211442138x51=99.4837673636768x52=−359.188760060433x53=26.1799387799149x54=−63.8790506229925x55=5.23598775598299x56=−89.0117918517108x57=82.7286065445312x58=−13.6135681655558x59=−80.634211442138x60=−74.3510261349584x61=86.9173967493176x62=24.0855436775217x63=−49.2182849062401x64=61.7846555205993x65=95.2949771588904x66=32.4631240870945x67=−7.33038285837618x1=38.7463093942741x2=13.6135681655558x3=11.5191730631626x4=−55.5014702134197x5=−30.3687289847013x6=−61.7846555205993x7=−86.9173967493176x8=89.0117918517108x9=−51.3126800086333x10=1.0471975511966x11=−68.0678408277789x12=36.6519142918809x13=−70.162235930172x14=93.2005820564972x15=−95.2949771588904x16=49.2182849062401x17=30.3687289847013x18=17.8023583703422x19=−32.4631240870945x20=−99.4837673636768x21=63.8790506229925x22=42.9350995990605x23=−225.147473507269x24=−93.2005820564972x25=−17.8023583703422x26=7.33038285837618x27=−11.5191730631626x28=57.5958653158129x29=−42.9350995990605x30=−24.0855436775217x31=70.162235930172x32=−36.6519142918809x33=−26.1799387799149x34=19.8967534727354x35=−76.4454212373516x36=76.4454212373516x37=−1.0471975511966x38=1651.43053823704x39=55.5014702134197x40=−5.23598775598299x41=51.3126800086333x42=45.0294947014537x43=68.0678408277789x44=−45.0294947014537x45=−82.7286065445312x46=−19.8967534727354x47=−57.5958653158129x48=74.3510261349584x49=−38.7463093942741x50=80.634211442138x51=99.4837673636768x52=−359.188760060433x53=26.1799387799149x54=−63.8790506229925x55=5.23598775598299x56=−89.0117918517108x57=82.7286065445312x58=−13.6135681655558x59=−80.634211442138x60=−74.3510261349584x61=86.9173967493176x62=24.0855436775217x63=−49.2182849062401x64=61.7846555205993x65=95.2949771588904x66=32.4631240870945x67=−7.33038285837618This roots
x52=−359.188760060433x23=−225.147473507269x20=−99.4837673636768x15=−95.2949771588904x24=−93.2005820564972x56=−89.0117918517108x7=−86.9173967493176x45=−82.7286065445312x59=−80.634211442138x35=−76.4454212373516x60=−74.3510261349584x13=−70.162235930172x11=−68.0678408277789x54=−63.8790506229925x6=−61.7846555205993x47=−57.5958653158129x4=−55.5014702134197x9=−51.3126800086333x63=−49.2182849062401x44=−45.0294947014537x29=−42.9350995990605x49=−38.7463093942741x32=−36.6519142918809x19=−32.4631240870945x5=−30.3687289847013x33=−26.1799387799149x30=−24.0855436775217x46=−19.8967534727354x25=−17.8023583703422x58=−13.6135681655558x27=−11.5191730631626x67=−7.33038285837618x40=−5.23598775598299x37=−1.0471975511966x10=1.0471975511966x55=5.23598775598299x26=7.33038285837618x3=11.5191730631626x2=13.6135681655558x18=17.8023583703422x34=19.8967534727354x62=24.0855436775217x53=26.1799387799149x17=30.3687289847013x66=32.4631240870945x12=36.6519142918809x1=38.7463093942741x22=42.9350995990605x42=45.0294947014537x16=49.2182849062401x41=51.3126800086333x39=55.5014702134197x28=57.5958653158129x64=61.7846555205993x21=63.8790506229925x43=68.0678408277789x31=70.162235930172x48=74.3510261349584x36=76.4454212373516x50=80.634211442138x57=82.7286065445312x61=86.9173967493176x8=89.0117918517108x14=93.2005820564972x65=95.2949771588904x51=99.4837673636768x38=1651.43053823704is the points with change the sign of the inequality expression.
First define with the sign to the leftmost point:
x0≤x52For example, let's take the point
x0=x52−101=
−359.188760060433+−101=
−359.288760060433substitute to the expression
cos(t)≤21cos(t)≤21cos(t) <= 1/2
Then
x≤−359.188760060433no execute
one of the solutions of our inequality is:
x≥−359.188760060433∧x≤−225.147473507269 _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____
/ \ / \ / \ / \ / \ / \ / \ / \ / \ / \ / \ / \ / \ / \ / \ / \ / \ / \ / \ / \ / \ / \ / \ / \ / \ / \ / \ / \ / \ / \ / \ / \ / \ /
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x52 x23 x20 x15 x24 x56 x7 x45 x59 x35 x60 x13 x11 x54 x6 x47 x4 x9 x63 x44 x29 x49 x32 x19 x5 x33 x30 x46 x25 x58 x27 x67 x40 x37 x10 x55 x26 x3 x2 x18 x34 x62 x53 x17 x66 x12 x1 x22 x42 x16 x41 x39 x28 x64 x21 x43 x31 x48 x36 x50 x57 x61 x8 x14 x65 x51 x38
Other solutions will get with the changeover to the next point
etc.
The answer:
x≥−359.188760060433∧x≤−225.147473507269x≥−99.4837673636768∧x≤−95.2949771588904x≥−93.2005820564972∧x≤−89.0117918517108x≥−86.9173967493176∧x≤−82.7286065445312x≥−80.634211442138∧x≤−76.4454212373516x≥−74.3510261349584∧x≤−70.162235930172x≥−68.0678408277789∧x≤−63.8790506229925x≥−61.7846555205993∧x≤−57.5958653158129x≥−55.5014702134197∧x≤−51.3126800086333x≥−49.2182849062401∧x≤−45.0294947014537x≥−42.9350995990605∧x≤−38.7463093942741x≥−36.6519142918809∧x≤−32.4631240870945x≥−30.3687289847013∧x≤−26.1799387799149x≥−24.0855436775217∧x≤−19.8967534727354x≥−17.8023583703422∧x≤−13.6135681655558x≥−11.5191730631626∧x≤−7.33038285837618x≥−5.23598775598299∧x≤−1.0471975511966x≥1.0471975511966∧x≤5.23598775598299x≥7.33038285837618∧x≤11.5191730631626x≥13.6135681655558∧x≤17.8023583703422x≥19.8967534727354∧x≤24.0855436775217x≥26.1799387799149∧x≤30.3687289847013x≥32.4631240870945∧x≤36.6519142918809x≥38.7463093942741∧x≤42.9350995990605x≥45.0294947014537∧x≤49.2182849062401x≥51.3126800086333∧x≤55.5014702134197x≥57.5958653158129∧x≤61.7846555205993x≥63.8790506229925∧x≤68.0678408277789x≥70.162235930172∧x≤74.3510261349584x≥76.4454212373516∧x≤80.634211442138x≥82.7286065445312∧x≤86.9173967493176x≥89.0117918517108∧x≤93.2005820564972x≥95.2949771588904∧x≤99.4837673636768x≥1651.43053823704