Examples, videos, activities, solutions, and worksheets that are suitable for A Level Maths to help students answer questions on trigonometric identities.
A-Level Edexcel C3 January 2008 Q6(a)
Worked solution to this question on trig. Identities
(a) Use the double angle formulae and the identity
cos(A + B) = cosA cosB - sinA sinB
to obtain an expression for cos 3x in terms of powers of cos x only
A-Level Edexcel C3 January 2008 Q6b(i)
Worked solution to this question on trig. Identities
(b)(i) Prove that
cos x/(1 + sin x) + (1 + sin x)/cos x = 2 sec x
A-Level Edexcel C3 January 2008 Q6b(ii)
Worked solution to this question on trig. Identities
(b)(ii) Hence find, for 0 < x < 2π, all the solutions of
cos x/(1 + sin x) + (1 + sin x)/cos x = 4
A-Level Edexcel C3 January 2008 Q7(a)
A curve C has equation
y = 3 sin2x + 4 cos2x, -π ≤ x ≤ π.
The point A(0, 4) lies on C.
(a) Find an equation of the normal to the curve C at A
A-Level Edexcel C3 January 2008 Q7(b)
Worked solution to this question on the Rsin(x+alpha) method.
(b) Express y in the form Rsin(2x + α), where R > 0 and 0 < α < π/2
Give the value of α to 3 significant figures