Question

If 0 < z ≤ 90 and sin(9z − 1) = cos(6z + 1), what is the value of z?

z = 3

z = 4

z = 5

z = 6

Answer 1

z=6

Explanation:

I took the test!

Answer 2

The value of z is:

z = 6

Explanation:

We have been given 4 options of z. Lets substitute each value in the given equation to see which option satisfies.

For z = 3

sin(9z - 1) = cos(6z + 1)

sin(9(3) - 1) = cos(6(3) + 1)

sin(26) = cos(19)

0.438 = 0.945

FALSE

For z = 4

sin(9z - 1) = cos(6z + 1)

sin(9(4) - 1) = cos(6(4) + 1)

sin(35) = cos(25)

0.574 = 0.965

FALSE

For z = 5

sin(9z - 1) = cos(6z + 1)

sin(9(5) - 1) = cos(6(5) + 1)

sin(44) = cos(31)

0.695 = 0.857

FALSE

For z = 6

sin(9z - 1) = cos(6z + 1)

sin(9(6) - 1) = cos(6(6) + 1)

sin(53) = cos(37)

0.799 = 0.799

TRUE