Find the coefficients of x7 and x8 in the expansion of .
To find : coefficients of x7 and x8
Formula :
Here, a=2,
We have,
To get a coefficient of x7, we must have,
x7 = xr
• r = 7
Therefore, the coefficient of x7
And to get the coefficient of x8 we must have,
x8 = xr
• r = 8
Therefore, the coefficient of x8
Conclusion :
• coefficient of x7
• coefficient of x8