展开 (xcos(β)+lycos(θ))^2+(xsin(β)-lsin(θ))^2

解答

展开

(x cos (β) + l y cos (θ))^{2} + (x sin (β) - l sin (θ))^{2}

x^{2} cos^{2} (β) + 2 l x y cos (β) cos (θ) + l^{2} y^{2} cos^{2} (θ) + x^{2} sin^{2} (β) - 2 l x sin (β) sin (θ) + l^{2} sin^{2} (θ)

求解步骤

(x cos (β) + l y cos (θ))^{2} + (x sin (β) - l sin (θ))^{2}

展开

(x cos (β) + l y cos (θ))^{2} : x^{2} cos^{2} (β) + 2 l x y cos (β) cos (θ) + l^{2} y^{2} cos^{2} (θ)

= x^{2} cos^{2} (β) + 2 l x y cos (β) cos (θ) + l^{2} y^{2} cos^{2} (θ) + (x sin (β) - l sin (θ))^{2}

展开

(x sin (β) - l sin (θ))^{2} : x^{2} sin^{2} (β) - 2 l x sin (β) sin (θ) + l^{2} sin^{2} (θ)

= x^{2} cos^{2} (β) + 2 l x y cos (β) cos (θ) + l^{2} y^{2} cos^{2} (θ) + x^{2} sin^{2} (β) - 2 l x sin (β) sin (θ) + l^{2} sin^{2} (θ)

e x p an d \frac{5 x ^{2} - 6 x + 7}{( x + 1 ) ( x ^{2} + 1 )}

e x p an d \frac{- 2 s ^{2} + 7 s - 2}{( s - 1 ) ^{2} ( s - 2 ) ( s ^{2} + 4 )}

e x p an d (x - 5) (x - 6 i)

\frac{d}{d r ( x )} ((x) (\frac{r ( x ) ^{2}}{4} - r (x) s + s^{2}))

e x p an d \frac{x ( - 2 ln ( x y ) + 1 )}{y ^{3}}