Verify the identiy, (cos(x+h) - sin x)/h = cos x * ((cos h - 1)/h)- sin x * (sin h /h)
96367
Intuition of Addition Formula for Sine and Cosine
149447
Proving $\sin (x)=\cos (90^\circ-x)$
136409
Verify $\int\sec x\ dx=\frac12 \ln \left\lvert\frac{1+\sin x}{1-\sin x}\right\rvert + C$
29604
How to solve $\sin x +\cos x = 1$?
91521
Ambiguity of notation: $\sin(x)^2$
145955
verifying an incorrect integrating factor
115229
Find the zeros of $h(z)=z^6-5z^4+3z^2-1$ within the unit disc - Verification
106643
problem using identity theorem
145559
Trigonometry problem on product of trig functions.
119628
Proving an identity relating to the complex modulus: $z\bar{a}+\bar{z}a \leq 2|a||z|$
122490
Proof of Parseval's identity
104384
Trigonometric identity: $\frac {\tan\theta}{1-\cot\theta}+\frac {\cot\theta}{1-\tan\theta} =1+\sec\theta\cdot\csc\theta$
127380
Use vectors to prove $\cos(\beta - \alpha) = \cos \alpha \cos\beta + \sin\alpha \sin\beta$
25569
Intuitive understanding of the derivatives of $\sin x$ and $\cos x$
21941
Proving: $x = a_0 + \sum_{n=1}^{\infty}(a_n \cos nx + b_n \sin nx)$
12653
Prove $\int\cos^n x \ dx = \frac{1}n \cos^{n-1}x \sin x + \frac{n-1}{n}\int\cos^{n-2} x \ dx$
48881
Verification the integral identity $\int_0^\pi \ln(1+\alpha\cos(x))dx=\pi\ln\left(\frac{1+\sqrt{1-\alpha^2}}{2}\right)$.