Prove-that-the-inequality-cos-x-1-sin-2-x-hold-true-for-all-x-R-

Question Number 108628 by I want to learn more last updated on 18/Aug/20

Prove that the inequality ∣ \cos x ∣ ⩾ 1 - \sin^{2} x hold true for all x \in R

Commented by mr W last updated on 18/Aug/20

∣ \cos x ∣⩽ 1

\Rightarrow∣ \cos x ∣⩾ \cos^{2} x = 1 - \sin^{2} x

Commented by I want to learn more last updated on 18/Aug/20

Thanks sir, i appreciate .

Commented by I want to learn more last updated on 18/Aug/20

please sir help with Q 108626

Commented by Aziztisffola last updated on 18/Aug/20

look at the answer to get an idea .