Edexcel C2 2011 January — Question 7

Exam BoardEdexcel
ModuleC2 (Core Mathematics 2)
Year2011
SessionJanuary
TopicTrig Equations

  1. (a) Show that the equation
$$3 \sin ^ { 2 } x + 7 \sin x = \cos ^ { 2 } x - 4$$ can be written in the form $$4 \sin ^ { 2 } x + 7 \sin x + 3 = 0$$ (b) Hence solve, for \(0 \leqslant x < 360 ^ { \circ }\), $$3 \sin ^ { 2 } x + 7 \sin x = \cos ^ { 2 } x - 4$$ giving your answers to 1 decimal place where appropriate.