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C1 exam question help

ImageUploadedByStudent Room1446398693.616308.jpg questions 4 mainly and 5


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Notnek
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Original post by lkjhgfdsasd
ImageUploadedByStudent Room1446398693.616308.jpg questions 4 mainly and 5


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Choose a question and post all your ideas/working and tell us where you are stuck.
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lkjhgfdsasd
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Original post by notnek
Choose a question and post all your ideas/working and tell us where you are stuck.


4 and all of it I have literally no idea what it's asking


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Original post by lkjhgfdsasd
ImageUploadedByStudent Room1446398693.616308.jpg questions 4 mainly and 5


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4a) is related to the discriminant and what it equals when the roots of an equation are equal
Original post by lkjhgfdsasd
ImageUploadedByStudent Room1446398693.616308.jpg questions 4 mainly and 5Posted from TSR Mobile


to solve question 4, you need to find the discriminant. in class you should have been told the discriminant is b^2-4ac. given that the question says the equation has equal roots, you can show m^2 - 8m + 12 = 0 by substituting in the values from x^2 + x(m+4) + (4m + 1) into b^2-4ac = 0 (it is equals because the equation only has one root). to answer the second part of the question, solve the equation given in the question by either factorising or using the quadratic formula.

to solve question 5, complete the square separately for the x and y terms. if you don't know how to complete the square, take note of this example. if you have x^2 + 3x + 2 = 0, you can write the equation in the form (x+a)^2 - b = 0 by inspecting the first two terms in the equation to get (x+3/2)^2, then you add the minus of the square of the last term in the bracket. e.g. (x+3/2)^2 - 9/4 + 2 = 0(x+3/2)^2 - 1/4 = 0
(edited 8 years ago)
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lkjhgfdsasd
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I'm soo confused on question 4 still and on 5 I've done
(x-4)^2-16+(y+3)^2-9=11
Then (x-4)^2+(y+3)^2=36 am I on the right track?


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Original post by lkjhgfdsasd
I'm soo confused on question 4 still and on 5 I've done
(x-4)^2-16+(y+3)^2-9=11
Then (x-4)^2+(y+3)^2=36 am I on the right track?


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given:
a = 1
b = m + 4
c = 4m + 1
try finding the discriminant. remember equal roots means there's only one root so set it equal to 0.
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lkjhgfdsasd
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I'm starting to understand where it's going but I'm still SO confused 😩


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Original post by lkjhgfdsasd
I'm starting to understand where it's going but I'm still SO confused 😩


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i recommend you watch this http://www.examsolutions.net/maths-revision/core-maths/algebra-and-functions/quadratics/roots/tutorial-1.php
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Avatar for lkjhgfdsasd
lkjhgfdsasd
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Oh my god I've got it 8263673 headaches after



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Oh my god I've got it 8263673 headaches after



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