Practicing Success
What is $\sqrt{(1-sinA)}\sqrt{(1+sinA)}$? |
$sec^2A$ secA + tanA $tan^2A$ cosA |
cosA |
$\sqrt{(1-sinA)}\sqrt{(1+sinA)}$ = $\sqrt{1 - sin^2A}$ (1 - sin²A = cos²A) = $\sqrt{cos^2A}$ = cosA Alternatively, take A = 45° $\sqrt{(1-sinA)}\sqrt{(1+sinA)}$ = $\sqrt{(1-sin45)}\sqrt{(1+sin45)}$ = $\sqrt{(1-\frac{1}{\sqrt{2}})}\sqrt{(1+\frac{1}{\sqrt{2}})}$ = $\frac{1}{\sqrt{2}}$ = cosA |