Maximum value of $4|\cos x|-3|\sin x|$
87489
Find range of $f(x)=3|\sin x|-4|\cos x|$
82321
Is $\cos(x) \geq 1 - \frac{x^2}{2}$ for all $x$ in $R$?
127004
Extreme of $\cos A\cos B\cos C$ in a triangle without calculus.
17751
Find the greatest value of $\arg z$ achieved on a circle in $\mathbb{C}$
33027
Maximum area of a square in a triangle
27513
Trigonometric bounds
44715
Exact value for $\cos 36°$
29604
How to solve $\sin x +\cos x = 1$?
28161
Solve $\lim_{x\to 0} \frac{\sin x-x}{x^3}$
108918
Can someone explain this trigonometric limit?
111696
Show $\sin x = bx$ has at least 3 real solutions.
122145
Evaluating Limit - $(1-(\cos x)^{\sin x})/(x^3)$
39752
Is there a limit of $\cos(n!)$?
46665
Solving $\cos x+\sin x-1=0$
128063
How to evaluate the limit $\lim_{x\to 0} \frac{1-\cos(4x)}{\sin^2(7x)}$
37158
upper limit of $\cos (x^2)-\cos (x+1)^2$ is $2$
53135
Find $4\cos\theta-3\sin\theta$, given that $4\sin \theta +3\cos \theta = 5$