NECO June/July 2024 - Get offline past questions & answers - Download objective & theory, all in one app 48789
Join your school's WhatsApp group

Determine the coefficient of \(x^{2}\) in the expansion of \((a + 3x)^{6}\).

Further Mathematics
WAEC 2011

Determine the coefficient of \(x^{2}\) in the expansion of \((a + 3x)^{6}\).

  • A. \(18a^{2}\)
  • B. \(45a^{4}\)
  • C. \(135a^{4}\)
  • D. \(1215a^{2}\)
Post-UTME Past Questions - Original materials are available here - Download PDF for your school of choice + 1 year SMS alerts
NECO June/July 2024 - Get offline past questions & answers - Download objective & theory, all in one app 48789
Join your school's WhatsApp group
Correct Answer: Option C
Explanation

\((a + 3x)^{6}\).

The coefficient of \(x^{2}\) is:

\(^{6}C_{4}(a)^{6 - 2} (3x)^{2} = \frac{6!}{(6 - 4)! 4!} (a^{4})(9x^{2})\)

\(15 \times a^{4} \times 9 = 135a^{4}\)


Report an Error Ask A Question Download App
Post-UTME Past Questions - Original materials are available here - Download PDF for your school of choice + 1 year SMS alerts
Join your school's WhatsApp group
Project Topics and Materials, Post-UTME past questions - Download now or upload yours to get paid

Contributions ({{ comment_count }})

Please wait...

{{ settings.no_comment_msg ? settings.no_comment_msg : 'There are no comments' }}

Quick Questions

Post your Contribution

Please don't post or ask to join a "Group" or "Whatsapp Group" as a comment. It will be deleted. To join or start a group, please click here

{{ quote.posted_by.display_name }}
{{ settings.form_textarea_description }}
 
Project Topics and Materials, Post-UTME past questions - Download now or upload yours to get paid
Post-UTME Past Questions - Original materials are available here - Download PDF for your school of choice + 1 year SMS alerts
NECO June/July 2024 - Get offline past questions & answers - Download objective & theory, all in one app 48789
Join your school's WhatsApp group
NECO June/July 2024 - Get offline past questions & answers - Download objective & theory, all in one app 48789
Post-UTME Past Questions - Original materials are available here - Download PDF for your school of choice + 1 year SMS alerts
Join your school's WhatsApp group
Project Topics and Materials, Post-UTME past questions - Download now or upload yours to get paid