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.
Hi, for Q9 (ii), I dont get the corrections starting from the 'since (4-m)^2>0' part. Why isnt 36 included and how do they know that it is bigger than 0? Thank you!
Date Posted: 4 years ago
Views: 314
This is because (4 - m)^2 is a perfect square and properties of a squared expression is such that its value cannot be negative. Howsoever you try to put a value of m, the output value cannot be negative.
Hence, (4 - m)^2 will have a lowest possible output value of 0 and this can be higher. We represent this by
(4 - m)^2 >= 0
for all real values of m. Note that this includes the output value 0 when m = 4. Otherwise, the expression would have a positive output. But let’s look at what happens when we put in the extra 36.
With the extra 36, the lowest possible value of (4 - m)^2 + 36 must be 36, for obvious reasons. In any case, this resultant output is already above the 0 output threshold, so (4 - m)^2 + 36 > 0 for all values of m.
Hence, (4 - m)^2 will have a lowest possible output value of 0 and this can be higher. We represent this by
(4 - m)^2 >= 0
for all real values of m. Note that this includes the output value 0 when m = 4. Otherwise, the expression would have a positive output. But let’s look at what happens when we put in the extra 36.
With the extra 36, the lowest possible value of (4 - m)^2 + 36 must be 36, for obvious reasons. In any case, this resultant output is already above the 0 output threshold, so (4 - m)^2 + 36 > 0 for all values of m.
See 1 Answer
done
{{ upvoteCount }} Upvotes
clear
{{ downvoteCount * -1 }} Downvotes
The perfect square thingy is very important for Sec 3 and Sec 4 A/E Maths.
Date Posted:
4 years ago
Oh I get it now! Thank you so muchhh
360 Tutoring Program