Prove that 12 cos(30°) - 2 tan(60°) can be written as √k where k is an integer, state the value of k.

Conversion of trigonometric functions:

cos(30°) = √3 / 2

tan(60°) = √3

Computing equation with trigonometric substitutions:

12 cos(30°) - 2 tan(60°) = 12 (√3 / 2) - 2 (√3) = (12 / 2) x √3 - 2√3 = 6√3 - 2√3 = 4√3

Rearranging into requested form:

4√3 = √42 x √3 = √16 x √3 = √48

Stating k:

√k = √48

k = 48

ND
Answered by Nic D. Maths tutor

7843 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

If f(x) = x^2, draw the graph of y = f(x) + 3


What is completing the square?


Solve the following simultaneous equations to find the values of x and y: 3y - 7x = 15 & 2y = 4x + 12


Solve the simultaneous equations. 2x+5y=-4 and 7x+y=19


We're here to help

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

MyTutor is part of the IXL family of brands:

© 2025 by IXL Learning