Show that sin2A is equal to 2sinAcosA

This question requires you to use the trigonometric identity sin(A+B)=sinAcosB + sinBcosA. The difficulty in this problem is noticing that you need to substitute 2A for A+A and then you can simply put this into the trig identity. Doing this leads to you sin2A=sinAcosA + sinAcosA which is 2sinAcosA.

SL
Answered by Samuel L. Maths tutor

33660 Views

See similar Maths A Level tutors

Related Maths A Level answers

All answers ▸

A hollow sphere of radius r is being filled with water. The surface area of a hemisphere is 3pi*r^2. Question: When the water is at height r, and filling at a rate of 4cm^3s^-1, what is dS/dT?


How do you integrate ln(x) ?


How do I identify that the coordinate (2,3) is the maximum point of the curve f(x)?


Write down three linear factors of f(x) such that the curve of f(x) crosses the x axis at x=0.5,3,4. Hence find the equation of the curve in the form y = 2(x^3) + a(x^2) + bx + c.


We're here to help

contact us iconContact ustelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

© MyTutorWeb Ltd 2013–2025

Terms & Conditions|Privacy Policy
Cookie Preferences