Question

If $a=\sec {10}^c$, then

• A. $a>0$
• B. $a<0$
• C. $a=0$
• D. none of these

Answer 1

The correct option is B $a<0$

Given : $a=\sec {10}^c$
We know that $1^c\approx {57}^{\circ }$
$\Rightarrow {10}^c\approx {570}^{\circ }$
$a=\sec {10}^c\approx \sec {570}^{\circ }\approx \sec {210}^{\circ }$
${210}^{\circ }$ lies in $3^{\text{rd}}$ quadrant, so
$\sec {10}^c<0$