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

7593 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

3 teas and 2 coffees have a total cost of £7.80 5 teas and 4 coffees have a total cost of £14.20 Work out the cost of one tea and the cost of one coffee.


y=6x+2 Find the gradient of the line and the y intersect


Solve these simultaneous questions: 2y+x =8 and y-2x = -1.


Solve the simultaneous equations 2x + y = 18 and x - y = 6


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