hey guys
So i am doing a past trial paper and got stuck on this question.
It has worked solutions as seen in the picture but I still don't understand how each step was reached.. if that makes sense?
I just need some help understanding the question or if there is a simpler way to do this question let me know please!
This is using the cosine rule
a
2=b
2+c
2+2bc cosA
a = BC, b = AC c= AB
Or in other words a= 90, b = c = x
A= 113º
That's how they get the first line
From there they just rearrange it. They get all the terms with x on one side (they already are though), all the terms without on another, then they factor out the x
2, get x
2 as the subject then square root both sides
If you're unsure about the cosine rule, you should brush up on it (don't know what's required for your course though) and if you still need help let me know. Rest is just rearranging the equation to make x the subject