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# How is this discriminant question 5k and not -3k? I am really confused. watch

1. Question is:

The equation kx^2 + kx + 3 - k = 0, where k is a constant, has no real roots.

a) Show that 5k^2 - 12k <0

Here is my solution. As you can see, I get the answer of -3k^2 -12k when I take a=k, b=k, c=3-k (using ax^2 + bx +c).

2. (Original post by blobbybill)
Question is:

The equation kx^2 + kx + 3 - k = 0, where k is a constant, has no real roots.

a) Show that 5k^2 - 12k <0

Here is my solution. As you can see, I get the answer of -3k^2 -12k when I take a=k, b=k, c=3-k (using ax^2 + bx +c).

Check the expansion of brackets ie -4k x -k is ...
3. Signs, the hardest part of C1 and C2. How I hated it.

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