Question

Equation = Sin (t + 12) = sin (90)
Question; solve t make t the subject

Answer 1

We have an equation

$$\text{sin} (t + 12) = \text{sin} (90).$$

The values of two sines can be equal only when their arguments (the part inside the parentheses) are equal, therefore, we can put that

$$t+12=90,\\ t=90-12=78.$$

The answer is $t=78$.