Question

Solve each equation for 0° < x < 360°.

cos(x+45°) + cos(x - 45°) = square root of 2

a. 45

b. 10

c.0

d.90

Answer 1

Hence value for x is 0 degree

Explanation:

Given:

x limits are (0 to 360) degrees and

Cos(x+45)+cos(x-45)=Sqrt(2)

To Find:

value for X

Solution:

Given equation cos(x+45)+ cos(x-45)

Is similar to cos(A+B) +cos(A-B)=2cosA*cosB

Now comparing with general formula we get ,

A=x and B=45

S

Hence given equation becomes as ,

`2cosA*cosB=Sqrt(2)`

`2Cosx*cos45=Sqrt(2)`

`cosx=Sqrt(2)/(2*cos45)..........cos45=1/`
`√(2)`

`Cosx=Sqrt(2)/Sqrt(2)`

`cosx=1`

x= 0

Hence value for x is 0 degree