How do you evaluate tan(pi/2+pi/6) . cot (pi-pi/6) . cos (pi/2-pi/6)?

1 Answer
Aug 13, 2016

Using identities for tan(A+B) and cos(A+B)

Explanation:

So tan(A-B)= "tanA-tanB"/"(1+tanAtanB)"
So cot(A-B) will be the reciprocal - "(1+tanAtanB)"/"tanA-tanB"
So A- pi and B is -pi/6
So =

"(tan(2pi/3)" x "(cos(pi/3))"x ("(1+tan(pi)tan(-pi/6))")/"tan(pi)-tan(-pi/6)"

= -sqrt3 x 1/2 x (\frac{1}{\sqrt{3}}0+1)/0-\frac{1}{\sqrt{3}}

Solving will give 1.5