[7971#87x-:71787],[1.sin(x^(2)+5)]

35 39 87 277 ? 5701

15, 38, 57, 74, 87, ?

Prove that : (0.87 x 0.87 x 0.87+0.13 x 0.13 x 0.13) / (0. 87 x 0.87-0.87 x 0.13+0.13 x 0.13)=1

Prove : (87xx87xx87+13xx13xx13)/(87xx87-87xx13+13xx13) =100

10.Using suitable identity prove that: qquad ((0.87)^(3)+(0.13)^(3))/((0.87)^(2)-(0.87times0.13)+(0.13)^(2))=1

Prove that :(0.87x0.87x0.87+0.13x0.13x0.13)/(0.87x0.87-0.87x0.13+0.13x0.13)=1

If [(x,x-y),(2x+y,7)]=[(3,1),(8,7)] write the value of y.

The value of cos(-89^(@))+cos(-87^(@))+cos(-85^(@))+…+cos(85^(@))+cos(87^(@))+cos(89^(@)) is equal to