Question

plzzz frds explain yeh 3 or root 22 kase aaya

Answer 1

Your answer is ----

according to cosine rule

${7}^{2} = {x}^{2} + {6}^{2} - 2 \times x \times 6 \cos(60) \\ \\ = > 49 = {x}^{2} + 36 - 12x \times \frac{1}{2} \\ \\ = > 49 - 36 = {x}^{2} - 6x \\ \\ = > {x}^{2} - 6x - 13 = 0$

Now , using quadratic formula [x=(-b±√b^2-4ac)/2a], we get

x = 3±√22

But x can't be negative

So,

x = 3+√22