The Student Room Group

Question on differentiation

I have posted the question and the answer. My question is - please can someone tell me how the author from madasmaths used similar triangles to find the length of PQ

Thank you very much
Reply 1
The two yellow triangles are similar.
Reply 2
The ratio a:2a should be the same as for (a-x):|PQ|.
Reply 3
Or 2aa=PQax \dfrac{2a}{a} = \dfrac{|\text{PQ}|}{a-x}.
Reply 4
Original post by GPiph
Or 2aa=PQax \dfrac{2a}{a} = \dfrac{|\text{PQ}|}{a-x}.

thank you

Quick Reply

Latest