Solve for X. sin (2x + 70) o= (cos x – 10) o

Answer 1

OK I apologize Christopher, it is the degree sign you

are putting...

But the right side does not look entirely correct..

the parenthesis are not correct.. the sine function

returns a number which CANNOT be a degree measure..

I shall ASSUME you mean cos(x-10)

The first problem was cos 42 = sin x

Then x = inverse_sine(cos 42)

= inverse_sine( sin(90-42)

= inverse_sine( sin(48))

= 48

sin (2x+70) = cos (x-10)

sin (2x+70) = sin (90 - (x-10))

sin (2x+70) = sin ( 90 -x + 10)

2x+70 = 100-x

3x+70 = 100

3x = 30

x=10

The solution CHECKS because, for x=10,

sin(2(10)+70)=

sin(20+70)=

sin(90) = 1

= cos(0) = cos(10-10) = cos(x-10)