Moderate -0.3 This is a straightforward binomial theorem application requiring students to equate two coefficients and solve for a constant. It involves standard formula recall and basic algebraic manipulation, making it slightly easier than average but not trivial since students must correctly identify and equate the appropriate terms.
In the expansion of \((2 + ax)^6\), the coefficient of \(x^2\) is equal to the coefficient of \(x^3\). Find the value of the non-zero constant \(a\). [4]
In the expansion of $(2 + ax)^6$, the coefficient of $x^2$ is equal to the coefficient of $x^3$. Find the value of the non-zero constant $a$. [4]
\hfill \mbox{\textit{CAIE P1 2014 Q1 [4]}}