Solve to find sin x , 4cos^2 + 7sin x -7 =0

4cos2 x + 7 sinx - 7 =0 we know that sin+ cos2 = 1 so 4(1-sin2x) + 7sinx -7 = 0 if we times out the brackets -4sin2x + 7 sinx -3 =0 4sin2x -7sinx +3 =0 (4sinx-1)(sinx +2)=0 so therefore sinx =1/4 or -2 however we know sinx cannot be less than -1 so answer is only 1/4

Answered by Jo P. Maths tutor

3227 Views

See similar Maths A Level tutors

Related Maths A Level answers

All answers ▸

How do you integrate ln(x) with respect to x?


What is the integral of x^2 sin(x) between the limits 0 and π/2


What is a stationary point and how do I find where they occur and distinguish between them?


Differentate sin(x^2+1) with respect to x


We're here to help

contact us iconContact usWhatsapp logoMessage us on Whatsapptelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

© MyTutorWeb Ltd 2013–2025

Terms & Conditions|Privacy Policy
Cookie Preferences