3.4.1 Sequences and Series (A-level only)

a.

Expand $(25+2x)12\displaystyle (25 + 2x)^{\frac{1}{2}}$ in ascending powers of $x\,$ up to and including the term in $x^3$ .

[4]

b.

Write down the range of values of $x\,$ for which the expansion is valid.

[1]

c.

Use your expansion, with a suitable value of $x$ , to find the value of $\sqrt{25.2}\,$ correct to 5 significant figures.

[2]

a.

Expand $(25+2x)12\displaystyle (25 + 2x)^{\frac{1}{2}}$ in ascending powers of $x\,$ up to and including the term in $x^3$ .

[4]

b.

Write down the range of values of $x\,$ for which the expansion is valid.

[1]

c.

Use your expansion, with a suitable value of $x$ , to find the value of $\sqrt{25.2}\,$ correct to 5 significant figures.

[2]

3.4.1 Sequences and Series (A-level only) Questions