Question

вычислить значение sina tga ctga если cosa = -9/41 и x/2

Answer 1

sina= (1-cos^2(a))^1/2= (1-(-9/41)^2)^1/2 =(1600/1681)^1/2=40/41

tga = sina/cosa = (40/41)(-9/41)= - 40/9 
 
ctga = cosa /sina = (-9/41)/(40/41) = - 9/40