I suspect a typo. You must have meant tan 4pi/9 = 5.6513
Hmmm. In fact, tan(4pi/9) = 5.6713
as before, cot(x) = tan(pi/2 - x)
cot(pi/18) = tan(pi/2 - pi/18) = tan(8pi/18) = tan(4pi/9)
you should write cot(pi/18) -- not (cot)pi/18
Now, part (b) is a little trickier. Recall that
tan(x-π) = (tanx - tanπ)/(1 + tanx tanπ) = tanx
So,
tan(13π/9) = tan(13π/9 - π) = tan(4π/9)
given that tan 4pi/7 = 5.6513, determine the following
a (cot)pi/18 b (tan)13pi/9
1 answer
1 answer