Saturday

August 30, 2014

August 30, 2014

Posted by **steve** on Tuesday, May 24, 2011 at 10:43pm.

A. 10th

B. 11th

C. 12th

D. 13th

- math -
**MathMate**, Wednesday, May 25, 2011 at 12:17amThe constant term is the term where the power of x in the product (1/(3x²))^r*x^(15-r) is zero, i.e.

(x^(-2))^r*x^(15-r)=x^0

=>

-2r+(15-r)=0

r=5

In general, a polynomial in x is written in descending order of the power of x.

So the powers of x for the expansion are:

x^0*(x^(-2))^15 = x^(-30)

...

x^10*(x^(-2))^5 = x^0

...

x^12*(x^(-2))^3 = x^6

x^13*(x^(-2))^2 = x^9

x^14*(x^(-2))^1 = x^12

x^15*(x^(-2))^0 = x^15

Can you figure out which term gives the constant term?

**Related Questions**

Math - Name School Team Event 3: Logic and Reasoning (with calculators) 5th/6th ...

maths - Given that the first term of an A.P is 7 and its 10th term is twice its ...

math - in an AP the 10th term is 54 and 5th term is 4 times the 2nd term . Find ...

10th grade - The common difference of an arithmetic sequence is 4. The 13th term...

arithmetic progression - given that the first term of an Ap is 7 and its 10th ...

arithmetic - given that the first term of an Ap is 7 and its 10th term is twice ...

Maths - The 14th term of an Ap is double the 4th term.find the 10th term if the ...

Math - the 12th term in a geometric sequence is 49, and the 14th term is 2401 . ...

math - The first term of an AP is 8. The ratio of d 11th term to the 7th term is...

math - d 9th term of an Ap is 52 while d 12th term is 70. find sum of it's 20th ...