Why do we have to use radians instead of degrees?

Radians are used a lot in A level maths because at higher levels, they allow for simplification of trigonometric functions. For example, when using radians, it can be said that:

Sin(angle) ≈ angle Cos(angle) ≈ 1 - 0.5*angle ≈ 1 Tan(angle) ≈ angle

In degrees for example, it can not be said that sin(30) ≈ 30, because sin(30)=0.5 and so the approximation is way off. But radians are defined in a way that means the above equations can be assumed true, and hence complex mathematical equations can be simplified allowing them to be solved.

JS

Related Maths A Level answers

All answers ▸

How do I integrate 4x*exp(x^2 - 1) with respect to x?


Can you teach me how to rationalise the denominator of an algebraic expression?


How do I remember the common values of cosx, sinx and tanx?


Two lines have equations r = (1,4,1)+s(-1,2,2) and r = (2,8,2)+t(1,3,5). Show that these lines are skew.