Question

Sin x = cos (3x + 20)

Answer 1

`x=17.5^o`

Explanation:

The question is

Find the value of x

we know that

If sin(A)=cos(B)

then

angle A and angle B are complementary angles

so

`A+B=90^o`

In this problem

`sin(x)=cos(3x+20)`

so

`x^o+(3x+20)^o=90^o`

solve for

`4x+20=90`

`4x=90-20`

`4x=70`

`x=17.5^o`