alanvaa
Can you please elaborate on this?
alanvaa Here is how to execute it fully.
Testing with m = 0:When \(m = 0\), the new roots become \(p\) and \(q\) (the original roots), so the equation should be the original: \(2x^2 - 5x + 2 = 0\), or when multiplied by \(2\): \(4x^2 - 10x + 4 = 0\).
Checking each option with \(m = 0\):
- A: \(4x^2 - 10x - 4 = 0\) ✗
- B: \(4x^2 - 10x + 4 = 0\) ✓
- C: \(4x^2 - 10x + 4 = 0\) ✓
- D: \(4x^2 - 10x - 4 = 0\) ✗
- E: \(4x^2 - 10x + 4 = 0\) ✓
This eliminates A and D, but B, C, and E all match.
You need a second test value.Testing with m = 1:When \(m = 1\), the new roots are \((p + q)\) and \((q + p)\) - these are
equal! So you have a repeated root.
From the original equation \(2x^2 - 5x + 2 = 0\), the sum of roots \(p + q = \frac{5}{2}\).
The equation with repeated root \(\frac{5}{2}\) is: \((x - \frac{5}{2})^2 = 0\)
Expanding: \(x^2 - 5x + \frac{25}{4} = 0\)
Multiply by \(4\): \(4x^2 - 20x + 25 = 0\)
Now check B, C, E with \(m = 1\):
- B: \(4x^2 - 20x + (-4 + 17 + 4) = 4x^2 - 20x + 17 = 0\) ✗
- C: \(4x^2 - 20x + (-4 - 17 + 4) = 4x^2 - 20x - 17 = 0\) ✗
- E: \(4x^2 - 20x + (4 + 17 + 4) = 4x^2 - 20x + 25 = 0\) ✓
Answer: EStrategic Takeaway:For abstract algebra problems with parameters:
- Test the simplest value first (often \(0\) or \(1\))
- If multiple options remain, test a second simple value
- Choose values that create special cases (like repeated roots or zero) - they're easier to verify
Hope this helps you.
You can practice similar questions
here (you'll find a lot of OG questions) - select Algebra - Quadratic Equations under Quant.