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

The value of z is:

z = 6

Step-by-step explanation:

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

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

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

sin(26) = cos(19)

0.438 = 0.945

FALSE

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

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

sin(35) = cos(25)

0.574 = 0.965

FALSE

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

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

sin(44) = cos(31)

0.695 = 0.857

FALSE

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

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

sin(53) = cos(37)

0.799 = 0.799

TRUE