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Login25 A Maths Questions from homework: NEED HELP!!!
10 posts
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Originally posted by SBS7484P:
i will post the questions is separate so its easier to see
Quesion 1 (roots of eqns):
NOTE: in this question, a = alpha sign, b = beta sign
the roots of the quadratic eqn 16x^2+ 7x+4=0 are a^2 and b^2
find:
i) 1/b^2
ii) two distinct quadrtic eqns whose roots are a and b
i) beats me. I dunno.ii) a^2 + b^2 = -(7/16)
(a^2)(b^2) = 1/4ab = 1/2 or -1/2
When ab = 1/2
(a+b)^2 = 9/16
a+b = 3/4 or - 3/4when ab = -1/2
(a+b)^2 = 23/16 (reject as it does not have a rational sq. root)Therefore,
Coefficient of x term = -1/2
Coefficient of constant = 3/4 or - 3/4
Therefore, eqns arex^2 - 1/2x + 3/4 = 0 and x^2 - 1/2x - 3/4 = 0
Multiply each by 44x^2-2x+3=0 and 4x^2-2x-3 = 0
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Originally posted by SBS7484P:
looked, tried, failed.=(That's because you give up too easily.
All these questions apply the same or similar concept. All you need is to understand the concept. Once you do, you can solve them.
Time to take out your text book and start reading and understanding.
Just take solving the questions as your life. We can't just simply give up on life everytime we encounter problems. We need to learn some "problem-solving" skill.
All the best!
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Originally posted by SBS7484P:
question 2:
find the value of m if the roots of the quadratic eqn x^2+2mx+m+2=0 are equal
U meant x^2?
in that case, it means the discriminant (b^2-4ac) = 0
In this case, a = 1, b = 2m and c = m+2
b^2-4ac = 4m^2-4(1)(m+2) = 0
4m^2-4m-8 = 0
m^2-m-2=0
(m-2)(m+1) = 0
m = 2 or -1
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