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.

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