What is the simplification value of $${cotA+tanB}\over{cotB+tanA}$$?

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

In ΔABC, ∠C=90° and CD is perpendicular to AB at D. If AD/BD=$$ {\sqrt{k}}$$, then AC/BC=?

 if $$\sqrt { 11- 3\sqrt { 8}}=a+b\sqrt { 2}$$, then what is the value of (2a+3b)?

Find the second diagonal of a rhombus when it’s first diagonal length is 12 cm and its side is 10 cm?

If the area of a circle is 9π sq.cm then it circumference is

P and Q are center of two circles with radii 9 cm and 2 cm respectively, where PQ = 17 cm, R is the center of another circle of radius x cm, which touches each of the above two circles externally. If ∠PRQ = 90 °, then the value of x is 

What value will come in place of question mark (?) in the following questions?

(?)² + 1 = 212 + 172