`cot7(1^(@))/2` is equal to

cot^(-1)(-2) is equal to

cot^(-1)(-2) is equal to

cot 7 1/2^@ is equal to

If the mapping f(x)=ax+b, a>0 maps [-1,1] on to [0,2] then cot[cot^(-1)(7)+cot^(-1)(8)+cot^(-1)(18)] is equal to

cot^(-1)(-1/2)+cot^(-1)(-1/3) is equal to

cot^(-1)(-1/2)+cot^(-1)(-1/3) is equal to

If the mapping f(x) = mx + c, m gt 0 maps [-1,1] onto [0,2] , then tan ( tan^(-1). 1/7 + cot ^(-1) 8 + cot ^(-1) 18) is equal to