maths
posted by Anonymous .
how to solve cos70/sin20+cos57cosec332cos60?

Did you notice that in the first two terms the angles mentioned are complimentary angles?
And did you know that cos 70 = sin 20 ?
so....
cos70/sin20+cos57cosec332cos60
= cos70/sin20 + cos57/sin33  2cos60
= sin20/sin20 + cos57/cos57  2cos60
= 1+1  2(1/2)
= 1