How can I calculate the maximum value of the compound angle formulae Rsin(x+a) and Rcos(x+a)?

Often, the compound angle formulae can seem quite offputting, especially since exam pressures can mean the random "R" at the front of an angle addition formulae appears confusing. However, finding the maximum (or minimum) for these formulae is relatively straightforward. If we let x+a=t, then we have Rsin(t) and Rcos(t). Thinking about the graphs for sine and cosine, we know that the maximum value that we can get on the y-axis is 1, so the maximum of sin(t) and cos(t) will be 1 (and the minimum will be -1). So, to get the maximum and minimum values, all we have to do is multiply by R. Hence, the maximum value of Rsin(x+a) will be R, and similarly for Rcos(x+a) the maximum value will be R.

LB
Answered by Luke B. Maths tutor

14399 Views

See similar Maths A Level tutors

Related Maths A Level answers

All answers ▸

Sketch, on a pair of axes, the curve with equation y = 6 - |3x+4| , indicating the coordinates where the curve crosses the axes, then solve the equation x = 6 - |3x+4|


Three forces (4i + 7j)N, (pi +5j)N and (-8i+qj) N act on a particle of mass 5 kg to produce an acceleration of (2i - j) m s 2 . No other forces act on the particle. Find the resultant force acting on the particle in terms of p and q. THEN find p and Q


p(x)=2x^3 + 7x^2 + 2x - 3. (a) Use the factor theorem to prove that x + 3 is a factor of p(x). (b) Simplify the expression (2x^3 + 7x^2 + 2x - 3)/(4x^2-1), x!= +- 0.5


If I have the equation of a curve, how do I find its stationary points?


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