Review question

# What (approximately) is the square root of $26$? Add to your resource collection Remove from your resource collection Add notes to this resource View your notes for this resource

Ref: R8065

## Suggestion

By making use of the relation $\delta y \approx \dfrac{dy}{dx} \times \delta x$, and without using tables, prove that $5.1$ is an approximate value of $\sqrt{26}$.

There is a convention in maths that $\delta y$ signifies ‘a small increase in $y$’.

We need to specify $y=f(x)$. Can we think of an appropriate $f(x)$, given that we’re trying to find $\sqrt{26}$?