NDA2022MathematicsBinomial TheoremActual
Paragraph: Consider the binomial expansion of (p+q x)^9 : Question: Under what condition the coefficients of x^2 and x^4 are equal?
Options
- Ap: q=7: 2
- Bp^2: q=7: 2
- Cp: q=2: 7
- Dp^2: q^2=2: 7
Correct answer
B. p^2: q=7: 2
Step-by-step solution
coefficient of x^2= coefficient of x^4 aligned & ^9 C₂ p^7 q^2= ^9 C₄ p^5 q^4 & 9.8 2.1 p^2= 9.8 .7 .6 4.3 .2 .1 q^2 & p^2 q^2 = 7 2 aligned