DaalChawal Messages 85 Reaction score 0 Thread starter Aug 14, 2021 #1 Doubt in marked step(Numerator) that how it came from first? Is there any alternative solution for this?
Doubt in marked step(Numerator) that how it came from first? Is there any alternative solution for this?
I like Serena Science Advisor Homework Helper MHB Messages 16,335 Reaction score 258 Aug 14, 2021 #2 We generally have $\sin^2x + \cos^2 x=1$. So $\sin^2x - i^2 \cos^2 x=1$ as well. Now substitute $x=\frac{2\pi}{9}$.
We generally have $\sin^2x + \cos^2 x=1$. So $\sin^2x - i^2 \cos^2 x=1$ as well. Now substitute $x=\frac{2\pi}{9}$.