2009 - WAEC Mathematics Past Questions and Answers - page 4

x = \(\frac{-1}{2}\)

x = 3

2x = -1, x = 3; 2x + 1 = 0

x - 3 = 0

(2x + 1)(x - 3) = 0

2x² - 6x + x - 3 = 0

2x² - 5x - 3 = 0

when y = 0, value of x = roots of the equation

x² - 5x + 4 = 0

x = 1, 4 (see graph)

h = ?

\(\frac{h}{5cm}\) = sin 45^o

h = 5cm x 0.6691 = 3.35cm

Area = \(\frac{1}{2}(a + b)\)h

where a = QR = 6cm

b = PA = 10cm

Area = \(\frac{1}{2}(6 + 10)\) x 3.35cm²

= \(\frac{1}{2}(16)\) x 3.35cm²

= 26.8cm²

= 27cm² (approx.)

Tan \(\theta = \frac{6}{6} = 1\)

\(\theta\) = tab - 1(1) = 45^o

< top = 20

= 2 x 45^o = 90^o

Now, t + 60^o + 50^o = 180^o

t = 180^o - 110^o

t = 70^o

Sum of exterior angles of a polygon = 360^o

(x + 64) + 2x + (3x - 54) + 5x + 4x + 3x + (2x + 10) = 360^o

20x + 20 = 360^o

20x + 360 - 20 = 340^o

x = \(\frac{340}{20}\)

x = 17^o

\(\frac{/PS/}{/PQ/} = \frac{/PT/}{/PR/}\)

\(\frac{x}{4 + x} = \frac{7}{7 + 5}\)

\(\frac{x}{4 + x} = \frac{7}{12}\)

(2x = 7)(4 + x); 12x = 28 + 7x

12x - 7x = 28

5x = 28

x = \(\frac{28}{5}\)

x = 5.6

The bearing of X from Y

= 360 - 120 = 240