book Maths Puzzle Numerical Ability

simplify these expressions:

(2cotB)/(1+cot^B)

the answer is supposed to be 2cosBsinB but i have no idea how that occurs.

Read Solution (Total 0)

book Other Question

What is the area of a triangle with the sides of 2.6 ft., 3.4 ft., and 4.1 ft. Can you help with this non-linear systems of equations
X^2 - Y^2 = 32
X - Y = 8

Thank you in advance.