## Ask Singapore Homework?

Upload a photo of a Singapore homework and someone will email you the solution for free.

## Question

secondary 3 | A Maths

** One Answer Below **

Anyone can contribute an answer, even non-tutors.

**Answer This Question**

how to do 18（c）and 19（b）？？helpp！

For Q19, it is important that the values of a must be positive.

This is because only smiley face graphs are capable of being 'always positive'.

Sad face graphs (a < 0) can never be 'always positive', while the case a = 0 leads to straight lines which is mainly assumed to never be 'always positive' (exceptions are horizontal lines above the x-axis).

In the case of the question, fortunately, the range a > 25/8 is already above zero, so no further manupulation is required.

### See 1 Answer

*done*{{ upvoteCount }} Upvotes

*clear*{{ downvoteCount * -1 }} Downvotes