Hello, mcinnes!

It's simple algebra . . . Exactly where is your difficulty?

The question is: When is ?A ball is thrown straight up.

Its height in metres after seconds is: .

To the nearest tenth of a second, when is the ball 6m above the ground?

Explain why there is two answers.

We have: .

Quadratic Formula: . seconds.

It attains a height of 6 meterson the way upandon the way down.