Mister Exam

Other calculators


cos(x/4)=sqrt(3)/2

cos(x/4)=sqrt(3)/2 equation

The teacher will be very surprised to see your correct solution 😉

v

Numerical solution:

Do search numerical solution at [, ]

The solution

You have entered [src]
           ___
   /x\   \/ 3 
cos|-| = -----
   \4/     2  
$$\cos{\left(\frac{x}{4} \right)} = \frac{\sqrt{3}}{2}$$
Detail solution
Given the equation
$$\cos{\left(\frac{x}{4} \right)} = \frac{\sqrt{3}}{2}$$
- this is the simplest trigonometric equation
This equation is transformed to
$$\frac{x}{4} = \pi n + \operatorname{acos}{\left(\frac{\sqrt{3}}{2} \right)}$$
$$\frac{x}{4} = \pi n - \pi + \operatorname{acos}{\left(\frac{\sqrt{3}}{2} \right)}$$
Or
$$\frac{x}{4} = \pi n + \frac{\pi}{6}$$
$$\frac{x}{4} = \pi n - \frac{5 \pi}{6}$$
, where n - is a integer
Divide both parts of the equation by
$$\frac{1}{4}$$
we get the answer:
$$x_{1} = 4 \pi n + \frac{2 \pi}{3}$$
$$x_{2} = 4 \pi n - \frac{10 \pi}{3}$$
The graph
Sum and product of roots [src]
sum
2*pi   22*pi
---- + -----
 3       3  
$$\frac{2 \pi}{3} + \frac{22 \pi}{3}$$
=
8*pi
$$8 \pi$$
product
2*pi 22*pi
----*-----
 3     3  
$$\frac{2 \pi}{3} \frac{22 \pi}{3}$$
=
     2
44*pi 
------
  9   
$$\frac{44 \pi^{2}}{9}$$
44*pi^2/9
Rapid solution [src]
     2*pi
x1 = ----
      3  
$$x_{1} = \frac{2 \pi}{3}$$
     22*pi
x2 = -----
       3  
$$x_{2} = \frac{22 \pi}{3}$$
x2 = 22*pi/3
Numerical answer [src]
x1 = -580.147443362915
x2 = -77.4926187885482
x3 = 2.0943951023932
x4 = 23.0383461263252
x5 = 379.085513533168
x6 = -23.0383461263252
x7 = 102.625360017267
x8 = 27.2271363311115
x9 = 52.3598775598299
x10 = 73.3038285837618
x11 = 98.4365698124802
x12 = -73.3038285837618
x13 = 77.4926187885482
x14 = -27.2271363311115
x15 = -8241.44472791722
x16 = -102.625360017267
x17 = -98.4365698124802
x18 = -2.0943951023932
x19 = 2892.359636405
x20 = -52.3598775598299
x21 = 274.365758413509
x22 = -3064.10003480124
x23 = 3470.41268466552
x24 = 48.1710873550435
x25 = -123.569311041199
x26 = -48.1710873550435
x27 = -152.890842474703
x27 = -152.890842474703
The graph
cos(x/4)=sqrt(3)/2 equation