## To find the phase shift of the function y = 5sin(4x - Ï€/2), you can use the formula c/b, where c represents the phase shift and b is the coefficient of x in the equation.

In this case, b = 4. Since c/b = Ï€/2, you need to divide Ï€/2 by 4:

Ï€/2 / 4 = Ï€/8

So the phase shift is Ï€/8.

You mentioned that your answer doesn't match Ï€/8 when you calculated c/b as Ï€/4. It seems that there might be confusion in your calculation. Ï€/4 is not equal to Ï€/8. In decimal form, Ï€/8 is approximately 0.3927, not 0.7854.

To convert Ï€/8 from radians to degrees, you multiply by 180/Ï€:

(Ï€/8) * (180/Ï€) = 22.5 degrees

Therefore, the phase shift is approximately 0.3927 radians or 22.5 degrees.

Remember to double-check your calculations to ensure accuracy.