Trigonometry MCQs

If A, B and C be the angles of a triangle, the incorrect relation is ?

What is the value of $$\frac{{\cos {{50}^ \circ }}}{{\sin {{40}^ \circ }}} + \frac{{3{\text{cosec}}\,{\text{8}}{0^ \circ }}}{{\sec {{10}^ \circ }}} - 2\cos {50^ \circ } \cdot {\text{cosec}}\,{40^ \circ }?$$

The value of sin²64° + cos64°sin26° + 2cos43°cosec47° is:

The value of θ(0 ≤ θ ≤ 90°) satisfying 2sin²θ = 3cosθ is?

If A is an acute angle, the simplified form of $$\frac{{\cos \left( {\pi - A} \right).\cot \left( {\frac{\pi }{2} + A} \right)\cos \left( { - A} \right)}}{{\tan \left( {\pi + A} \right)\tan \left( {\frac{{3\pi }}{2} + A} \right)\sin \left( {2\pi - A} \right)}}\,{\text{is:}}$$

Find $$\cos \left( { - \frac{{7\pi }}{2}} \right) = ?$$

The value of $$\frac{{\sin {{23}^ \circ }\cos {{67}^ \circ } + \sec {{52}^ \circ }\sin {{38}^ \circ } + \cos {{23}^ \circ }\sin {{67}^ \circ } + {\text{cosec}}\,{{52}^ \circ }\cos {{38}^ \circ }}}{{{\text{cose}}{{\text{c}}^2}\,{{20}^ \circ } - {{\tan }^2}{{70}^ \circ }}}{\text{ is:}}$$

a, b, c are the lengths of three sides of a triangle ABC. If a, b, c are related by the relation a² + b² + c² = ab + bc + ca, then the value of (sin²A + sin²B + sin²C) is?

What is the value of $$\frac{{\sin \left( {A + B} \right)}}{{\sin A\cos B}}?$$