Page 13 - 10-Math-1 QUADRATIC EQUATIONS

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Solving by quadratic formula, we have Version 1.1

x -=7 ± (7)2 - 4(1)(11) or x -7 ± (7)2 - 4(1)(-9)
2(1) 2(1)

= -=7 ± 49 - 44 -7 ± 5 = -7 ± 49 + 36 = -7 ± 85
22 22

∴ The solution set is  -7 ± 5, -7 ± 85 
 2 
 2 

EXERCISE 1.3

Solve the following equations

1. 2x4 - 11x2 + 5 = 0 2. 2x4 = 9x2 - 4

3. 5x1/2 = 7x1/4 - 2 4. x2/3 + 54 = 15x1/3

11. 2x4 + x3 - 6x2 + x + 2 = 0 12. 4.22x + 1 - 9.2x + 1 = 0

13. 32x+2 = 12.3x - 3 14. 2x + 64.2-x - 20 = 0

15. (x + 1) (x + 3) (x - 5) (x - 7) = 192

16. (x - 1)(x - 2)(x - 8)(x + 5) + 360 = 0

1.5 Radical equations

An equation involving expression under the radical sign is called
a radical equation. e.g.,

1.5 (i) Equations of the type:

Note: Extraneous root is introduced either by squaring the given
equation or clearing it of fractions.

Example 1: Solve the equation .

Solution: (i)

Squaring both sides of the equation (i), we get

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