What is the simplified value of (1– sin A cos A)(sin A + cos A)?

If 4sin² θ – 1 = 0 and angle θ is less than 90⁰. The value of cos² θ + tan² θ is:
(Take 0⁰ < θ < 90⁰) 

One angle of a triangle is 55°. If the other two angles are in the ratio 9:16, find the angles?

Which of the following simplification value of $$ {(secA-cosA)^{2}}+{(cosecA-sinA)^{2}}-{(cotA-tanA)^{2}}$$ ?

If $$ {tan3A=cot{(2A+40)}}$$ then find the value of $$ {tan^2{3A}}+{cot^{4}3A}$$.

If $${(2cos^3 A-cosA)\over (sin A- 2 sin^3 A)=1}$$ then what is the value of A?

$$ {3tan^{2}30°}-{4\over 3}{sin^{2}60°}- {1\over2}{cosec^{2}45°}+{4\over3}{sin^{2}90°=?}$$

If x+ y=90°, then what is  the value of $$ {\sqrt{cosx.cosecy-cosx.siny}}$$?