why is sin(x) squared plus cos(x) squared 1?

Thinking of sine and cosine as ratios of side lengths in a right angled triangle, sin(x) = o/h and cos(x) = a/h, so the sin(x)^2 + cos(x)^2 becomes (o^2 + a^2)/h^2. By Pyhtagoras, o^2 + a^2 = h^2, so we get h^2/h^2 = 1.

sin/cos = tan is derived similarly, sin/cos = (o/h)/(a/h) = o/a = tan

Answered by Matthew S. Maths tutor

12169 Views

See similar Maths A Level tutors

Related Maths A Level answers

All answers ▸

The line L has equation 7x - 2y + 11 = 0, Find the gradient of l


Differentiate the equation y = x^2 + 3x + 1 with respect to x.


Integrate sin^2(x) with respect to x


Use the quotient rule to differentiate: ln(3x)/(e^4x) 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 2013–2024

Terms & Conditions|Privacy Policy