Vinod Singh and Shweta Pawar Solutions for Chapter: Trigonometric Functions-I, Exercise 1: Classical Thinking

The value of $\frac{{\sin }^{2}20°+{\cos }^{4}20°}{{\sin }^{4}20°+{\cos }^{2}20°}$ is

If $x=a\cos \theta +b\sin \theta$ and $y=a\sin \theta -b\cos \theta$, then $a^2+b^2$ is equal to

If $x=a{\cos }^3\theta , y=b{\sin }^3\theta$, then

If $\cos x+{\cos }^2 x=1$, then the value of ${\sin }^2 x+{\sin }^4 x$ is

If $\sin x+{\sin }^{2}x=1$, then ${\cos }^{8}x+2 {\cos }^{6}x+{\cos }^{4}x=$

Which one of the following is incorrect?

Which of the following is possible?

The smallest value of $5\cos \theta +12$ is