$$\lim_{x\to0}\left(\frac{1}{x}-\tan\left(90-x\right)\right)$$

$$\lim_{x\to7}\left(x+8\right)$$

$$3\:-18\:-12\:+\:5\:+\:3$$

$$12x>-60$$

$$4m+2m^2+2m+6$$

$$\left(3cosx-9sinx\right)^2+\left(9cosx+3sinx\right)^2=90$$

$$\csc\left(x\right)^2\tan\left(2x\right)=\frac{2\cos\left(x\right)}{\cos\left(2x\right)\sin\left(x\right)}$$