Can some one help me with this trigonometry problem? CotA + cot(60+A)-cot(60-A)=3cot3A
how can i prove this ?

If f(x) = 2x + 8 and g(x) = x4, what is (gº)?

Tom can paint the fence in 12 hours, but if he works together with a friend they can finish the job in 8 hours. how long would it take for his friend to paint this fence alone?

The length of the line segment ac is 8x-9 what is the value of x