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Why bother with a post grad course - waste of time? 17-10-2016
1. Given that the equation,
x² - kx + 5 = 0, k>0 has equal roots. Find the value of k in the form a√b where a and b are integers. (4)can anyone please give me a step by step tutorial on how to solve this question.
Thank you
2. Help given, edited to remove full solution as it's against the rules
3. (Original post by Swifty139)
Given that it has equal roots, you should know that the discriminant; b^2 - 4ac, is equal to 0.

Quadratics are in the form ax^2 + bx + c = 0, so in this case we have a=1, b=-k and c=5. Therefore using our equation:

(-k)^2 - 4(1)(5) = 0

k^2 - 20 = 0

k^2 = 20

k = root20

k = 2root5
Oh I just found it difficult due to the wording in the question, but thank you very much now i understand the concept. I appreciate you giving me a step by step solution on how to solve this problem
4. (Original post by Swifty139)
Given that it has equal roots, you should know that the discriminant; b^2 - 4ac, is equal to 0.

Quadratics are in the form ax^2 + bx + c = 0, so in this case we have a=1, b=-k and c=5. Therefore using our equation:

(-k)^2 - 4(1)(5) = 0

k^2 - 20 = 0

k^2 = 20

k = root20

k = 2root5
Don't post full solutions.
5. (Original post by RDKGames)
Don't post full solutions.
Why not? Is there some rule i'm unaware of?
6. (Original post by Swifty139)
Why not? Is there some rule i'm unaware of?
It's against the forum rules. Refer to the stickies at the top of the forum.

http://www.thestudentroom.co.uk/show...9#post64637319

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