Question 13

(a) Copy and complete the following table of values for \(y = 9 \cos x + 5 \sin x\) to one decimal place.

x 30° 60° 90° 120° 150° 180° 210°
y   10.3     -0.2 -5.3   -10.3

(b) Using a scale of 2cm to 30° on the x- axis and 2 cm to 1 unit on the y- axis, draw the graph of \(y = 9 \cos x + 5 \sin x\) for \(0° \leq x \leq 210°\).

(c) Use your graph to solve the equation: (i) \(9\cos x + 5\sin x = 0\); (ii) \(9\cos x+ 5\sin x = 3.5\), correct to the nearest degree.

(d) Find the maximum value of y correct to one decimal place.

 

Theory

Question details

Exam body
WAEC
Subject
Mathematics
Year
1999
Question no.
#13
Type
Theory

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