F4 Maths - 2

KLCHAN_JOHN

2007-03-31 9:41 am

Question 1
If g(x) is divisible by (x-3), then g(x+1) is divisible by ==> A. x - 2 B. x - 3 C. x + 2 D. x +3
Solution below correct or not?. Please kinly explains
g(3) = 0
Now g (x+1) = 0, such that x = 2
Therefore, the answer is A. x - 2.

Question 2
Which of the following equations cannot be reduced to a quadratic equation?
A. x+2+ (1/(x-2)) =2
B. 4^x - 2^(x+3) - 1 =0
C. (x-4)^0.5 - x = 4
D. 1/x + 1/(x+2) + 1/(x+3) = 1/4

回答 (1)

匿名

2007-03-31 1:40 pm

✔ 最佳答案

Question 1
g(x) is divisible by (x-3), so g(x+1) is divisible by (x+1)-3 [replace x by (x+1)]
Therefore, the answer is A. x - 2.

Question 2
D. 1/x + 1/(x+2) + 1/(x+3) = 1/4 cannot be reduced to a quadratic equation because you will get cubic term

p.s.
A can be reduced to a quadratic equation if you multiply the whole equation by (x-2)
B can be reduced to a quadratic equation if you move 1 to another side, take log of both sides(you will get an affine equation/straight line), and multiply by x+a, where a can be any constant
C can be reduced to a quadratic equation if you move x to another side and square both sides

參考: myself

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