Come valuti #tan (pi / 3) #?

By evaluate I am assuming you mean give the#color(blue)" exact value"#

Obviously from a calculator the #tan(pi/3)≈1.732#
But to obtain the exact value we can use the following#color(blue)" Exact value triangle"#

From this triangle we can obtain the exact values for sin/cos/tan of the angles#pi/3" and "pi/6#. These are very useful and appear on many occasions so worth memorising for future use.

From triangle we obtain.

#tan(pi/3)=sqrt3/1=sqrt3#

For the same angle : #sin(pi/3)=sqrt3/2 , cos(pi/3)=1/2#