展开 (sin(a)+sin(b))^2+cos(a)-cos(b)

解答

展开

(sin (a) + sin (b))^{2} + cos (a) - cos (b)

sin^{2} (a) + 2 sin (a) sin (b) + sin^{2} (b) + cos (a) - cos (b)

求解步骤

(sin (a) + sin (b))^{2} + cos (a) - cos (b)

使用完全平方公式:

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

(sin (a) + sin (b))^{2} = sin^{2} (a) + 2 sin (a) sin (b) + sin^{2} (b)

= sin^{2} (a) + 2 sin (a) sin (b) + sin^{2} (b) + cos (a) - cos (b)

e x p an d \frac{4 ( - 3 s ^{2} + 12 s - 8 )}{( s ^{2} - 4 s + 8 ) ^{3}}

s im pl i f y (3 + 4 i)^{10}

e x p an d (sec (A) - tan (A))^{2}

e x p an d \frac{1}{( e ^{0.3 j} - 0.2 ) ( e ^{0.3 j} - 0.9 )}

e x p an d \frac{x cot ( x ) ln ( x ) - ln ( sin ( x ) )}{( ln ( x ) ) ^{2}}