### Questions (524)

 9 A spherical ball of salt is dissolving in water 8 The sum of digits in a 2-digit number 8 Prove: If $x+y+z=xyz$ then $\frac {x}{1-x^2} +\frac {y}{1-y^2} + \frac {z}{1-z^2}=\frac {4xyz}{(1-x^2)(1-y^2)(1-z^2)}$ 8 Help with this trigonometry problem 7 Integrate $\int \frac {\sin (2x)}{(\sin x+\cos x)^2}\,dx$

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 2 Prove that $\sin^4\theta+\cos^4\theta=\frac{3+\cos4\theta}{4}$ 1 Please help me Prove the identity, I keep getting the same answer no matter what 1 Product of two matrices 1 Right Triangle: Given hypotenuse and ratio of legs, find legs 1 Locus of mid point of a segment

### Tags (112)

 5 trigonometry × 103 1 exponentiation 2 geometry × 51 1 inverse 1 matrices × 10 1 alternative-proof 1 fractions × 6 0 calculus × 117 1 factoring × 2 0 analytic-geometry × 87

### Bookmarks (3)

 1 In a triangle ABC, prove that cot(A/2)+cot(B/2)+cot(C/2) =cot(A/2)cot(B/2)cot(C/2) 0 If $\frac {x}{a}=cos (\theta -\alpha)$.. Hello anyone there. Please help to solve. 0 Arithmetic Questions: