Question

Q5.

Heres a formula
r = √(w² − h² )
Work out the value of r when w=9√2 and h=5root6.
Give your answer in the form
a√b
where a and b are integers greater than 1.

Answer 1

r = 2
`√(3)`

Explanation:

using the rules of radicals

`√(a)` ×
`√(b)` ⇔
`√(ab)`

(
`√(x)` )² = x

substitute the given values of w and h into the equation

r =
`√(w^2-h^2)`

=
`\sqrt{(9√(2))^2-(5√(6))^2 }`

=
`√(162-150)`

=
`√(12)`

=
`√(4(3))`

=
`√(4)` ×
`√(3)`

= 2
`√(3)`