Question

1 + $ta{n}^{2}A$ = $se{c}^{2}A$ is valid for which of the following ranges

• A. 0 $<$ A $<$ 90
• B. 0 $<$ A $\le$ 90
• C. 0 $\le$ A $<$ 90
• D. 0 $\le$ A $\le$ 90

Answer 1

The correct option is C

0 $\le$ A $<$ 90

At A = ${90}^{\circ }$, tan A and sec A are not defined. So, A = ${90}^{\circ }$ cannot be included in the range. For A = $0^{\circ }$, sec A and tan A are valid and also secA and tan A exists for any angle between $0^{\circ }$ and ${90}^{\circ }$.