3.4 Sequences and Series (A-level only)

Find the coefficient of $x^5\,$ in the expansion of $2 + 3x)^7$ .

[2]

b(i).

Expand $\sqrt{1 - 2x}\,$ in ascending powers of $x\,$ as far as the term in $x^3$ .

[3]

b(ii).

State the range of values of $x\,$ for which your expansion is valid.

[1]

b(iii).

Use your expansion, with $x = 0.01$ , to find an estimate for $\sqrt{98}\,$ correct to five significant figures.

[2]

Find the coefficient of $x^5\,$ in the expansion of $2 + 3x)^7$ .

[2]

Expand $\sqrt{1 - 2x}\,$ in ascending powers of $x\,$ as far as the term in $x^3$ .

[3]

State the range of values of $x\,$ for which your expansion is valid.

[1]

Use your expansion, with $x = 0.01$ , to find an estimate for $\sqrt{98}\,$ correct to five significant figures.

3.4 Sequences and Series (A-level only)

3.4 Sequences and Series (A-level only) Questions