The Student Room Group

Edexcel C3 Trig identities question

Q 8a

http://qualifications.pearson.com/content/dam/pdf/A-Level/Mathematics/2013/Exam-materials/6665_01_msc_20150812.pdf

I can get to cos^2A + sin^2A + 2sinAcosA line (3 from bottom)

However how do they magically jump from this to the next line??
Original post by ShivP_98
Q 8a

http://qualifications.pearson.com/content/dam/pdf/A-Level/Mathematics/2013/Exam-materials/6665_01_msc_20150812.pdf

I can get to cos^2A + sin^2A + 2sinAcosA line (3 from bottom)

However how do they magically jump from this to the next line??


This is basically a2+b2+2ab=(a+b)2=(a+b)(a+b)a^2+b^2+2ab = (a+b)^2=(a+b)(a+b)

And denominator is the difference of two squares.

Quick Reply

Related discussions

Latest

Trending

Trending

Articles for you