Examveda If A is an acute angle and cotA + cosecA = 3, then the value of sinA is? A. 1B. $$\frac{4}{5}$$C. $$\frac{3}{5}$$Answer: Option C Solution (By Examveda Team) $$\eqalign{ & {\text{According to the question,}} \cr & {\text{cosec A}} + {\text{cot A}} = 3 \cr & {\text{cosec A}} - {\text{cot A}} = \frac{1}{3} \cr & \overline {2{\text{cosec A}}\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\, = \frac{{10}}{3}} \cr & {\text{cosec A}} = \frac{{10}}{6} \cr & {\text{sin A}} = \frac{6}{{10}} \cr & {\text{sin A}} = \frac{3}{5} \cr} $$ This Question Belongs to Arithmetic Ability >> Trigonometry
Solution (By Examveda Team) $$\eqalign{ & {\text{According to the question,}} \cr & {\text{cosec A}} + {\text{cot A}} = 3 \cr & {\text{cosec A}} - {\text{cot A}} = \frac{1}{3} \cr & \overline {2{\text{cosec A}}\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\, = \frac{{10}}{3}} \cr & {\text{cosec A}} = \frac{{10}}{6} \cr & {\text{sin A}} = \frac{6}{{10}} \cr & {\text{sin A}} = \frac{3}{5} \cr} $$
The equation $${\cos ^2}\theta $$ = $$\frac{{{{\left( {x + y} \right)}^2}}}{{4xy}}$$ is only possible when ? A. x = -yB. x > yC. x = yD. x < y View Answer
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