3 boxes of 12″ =36 = 2 boxes of 18″
so shortest height at which the 2 stack will be the same height =36 inches
-18 + x = -11
Let's add 18 to both sides
x = 7
Answer:
Explanation:
Identity: sec2θ=1+tan2θ
sec2(π2−x)−1=1+tan2(π2−x)−1
=tan2(π2−x)
Identity: tan(π2−θ)=cotθ
=cot2x
