Mathematics and Mathematical Literacy - Thutong

Mathematics(NSC)/Grade 12/ P2 38 ExemplarQUESTION 44.1sin 3θ= sinθ1 + 2cos2θ4.1.1 Prove the above identity. (6)4.1.2 Why is the identity not valid for θ = 60° (2)4.1.3 Without any further calculations, determine another value of θ forwhich the identity will not be valid. (1)4.2 In the figure, TC is a verticaltower. Two wires leading fromthe top of the tower are stakedat position A and position B sothat A; B and C are all in thesame horizontal plane. Theangles TAB and TBA aremeasured and found to be βand θ respectively. Thedistance between the stakes isx metres. If the angle ofelevation from stake A to thetop of the tower is α, calculatethe height of the tower in termsof x; β; θ and α .AxβθBαTC(5)[14]Copyright reserved