Question

If Sin 3x= Cos (x-60), find the value of x​

Answer 1

Answer:

x = 15

Step-by-step explanation:

Assuming 3x and x-60 are in degrees, you can use:

cos(a) = sin(a+90)

To rewrite the equation as:

sin(3x) = sin(x-60+90)

sin(3x) = sin(x+30)

3x = x+30

2x = 30

x = 15

But, solving 3x = x+30 which simplifies to x=15 is not the only solution to this equation, as you can see in below picture. Finding all solutions is a bit more work, but maybe that is not required in your case.