展开 (sin(t)-cos(2t))^2

解答

展开

(sin (t) - cos (2 t))^{2}

sin^{2} (t) - 2 cos (2 t) sin (t) + cos^{2} (2 t)

求解步骤

(sin (t) - cos (2 t))^{2}

使用完全平方公式:

(a - b)^{2} = a^{2} - 2 ab + b^{2}

(sin (t) - cos (2 t))^{2} = sin^{2} (t) - 2 sin (t) cos (2 t) + cos^{2} (2 t)

= sin^{2} (t) - 2 sin (t) cos (2 t) + cos^{2} (2 t)

= sin^{2} (t) - 2 cos (2 t) sin (t) + cos^{2} (2 t)

e x p an d (2, 3 i) (2, - 3 i)

e x p an d (e^{j t} - e^{- j t})^{5}

e x p an d (y^{3} + k x y^{4} - 10 x) d x + (3 x y^{2} + 29 x^{2} y^{3})

e x p an d \frac{d}{d x} ((2 - x^{2}) cos (x^{2})) + 2 x sin (x^{2})

e x p an d (1 + tan (x))^{3}