Помогите найти первообразную функции
1) F(X)=2x-5x
2)F(X)=3cosx-x
3)F(X)=cos5x-1/6sin3x

F(x)=2x-5x∫ 2x-5x dx = x²- (5/2)x²+Cf(x)=x²-(5/2)x²+CF(x)=3cos(x)-x∫ 3cos(x)-x dx = 3∫ cos(x) dx - ∫ x dx = 3sin(x)-(1/2)x²+Cf(x)=3sin(x)-(1/2)x²+C F(x)=cos5x-1/6sin3x∫ cos5x - 1/6sin3x dx = 1/5 sin5x+1/18cos3x+Cf(x)=1/5sin5x+1/18cos3x+C