Question

25 = 2(k)⁴ - 3(k)² + 5
Find K. Please show detailed working!
Thanks.

Answer 1

Answer:

0 = 2k^4 - 3k^2 - 20

0 = 2k^4 + 5k^2 - 8k^2 - 20

k^2(2k^2 + 5) -4(2k^2 +5) = 0

(k^2-4)(2k^2 + 5)=0

Therefore, k^2 is either 4 or -5/2

But k^2 is the square of a number and can't be negative.

Therefore, k^2 = 4

So, k = $\sqrt{4}$

Therefore, k=2.

Hope this helps.