Question

If 0 < b ≤ 90 and cos(11b + 2) = sin(12b − 4), what is the value of b? b = 3 b = 4 b = 5 b = 6

Answer 1

Answer:

$b = 6$

Step-by-step explanation:

Given

$0<b\le 90$

$\cos(11b + 2) = \sin(12b - 4)$

Required

Find b

To solve this, we make use of the following trigonometry rule:

If $\cos(\alpha) = \sin(\beta)$

Then: $\alpha + \beta = 90$

So:

$11b + 2 = 12b - 4$

Collect like terms

$11b - 12b = - 4 - 2$

$-b = - 6$

Multiply both sides by -1

$b = 6$