Prove that: $\cos \left(270°-A\right)=-\sin A$ and $\cot \left(270°-A\right)=\tan A$.

Important Questions on Trigonometrical Ratios of Angles of any Size and Sign

EASY

JEE Main

IMPORTANT

Plane Trigonometry Part 1>Chapter 5 - Trigonometrical Ratios of Angles of any Size and Sign>EXAMPLES X>Q 39

Prove that $\cos A+\sin \left({270}^{\circ }+A\right)-\sin \left({270}^{\circ }-A\right)+\cos \left({180}^{\circ }+A\right)=0$.

EASY

JEE Main

IMPORTANT

Plane Trigonometry Part 1>Chapter 5 - Trigonometrical Ratios of Angles of any Size and Sign>EXAMPLES X>Q 40

Prove that: $\sec \left({270}^{\circ }-A\right)\sec \left({90}^{\circ }-A\right)-\tan \left({270}^{\circ }-A\right)\tan \left({90}^{\circ }+A\right)+1=0$.

EASY

JEE Main

IMPORTANT

Plane Trigonometry Part 1>Chapter 5 - Trigonometrical Ratios of Angles of any Size and Sign>EXAMPLES X>Q 41

Prove that: $\cot A+\tan \left({180}^{\circ }+A\right)+\tan \left({90}^{\circ }+A\right)+\tan \left({360}^{\circ }-A\right)=0$.