Answer:
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Step-by-step explanation:
Answer:
b) i) Curve A
ii) - 1.75
iii) x = 1 - √5 or x = 1 + √5
Step-by-step explanation:
b) i) We are given a function y = x² - 2x - 3 and the graph of this function is also shown in the side diagram.
The equation can be rearranged to y = (x - 1)² - 4
⇒ (x - 1)² = y + 4
Therefore, this is an equation of a parabola having the vertex at (1,-4) point and its axis is parallel to the positive y-axis.
So, the curve A represents the equation given. (Answer)
ii) Now, at x = 2.5, f(x) = 2.5² - 2 × 2.5 - 3 = - 1.75 (Answer)
iii) When y = 1, then x² -2x - 3 = 1
⇒ x² - 2x - 4 = 0
⇒ (x - 1)² - 5 = 0
⇒ (x - 1)² - (√5)² = 0
⇒ (x - 1 + √5)(x - 1 - √5) = 0
⇒ x = 1 - √5 or x = 1 + √5 (Answer)
Answer:
Step-by-step explanation:
<em>1) y ≥ x/2</em>
<em>2) y ≤ -x</em>
<em>3) x ≥ 0</em>
Answer:
x = - 4 , x = - 3
Step-by-step explanation:
- 7x = x^2 + 12
Take all terms to one side of equation.
x^2 + 7x + 12 = 0
Find which 2 numbers multiply to give 12 and add to give 7.
a × b = 12
a + b = 7
a = 4
b = 3
Split the middle term using these 2 numbers.
x^2 + 4x + 3x + 12 = 0
Factorise each pair of terms separately.
x ( x + 4 ) + 3 ( x + 4 ) = 0
Bring out common factor of ( x + 4 ) and factorise.
( x + 4 ) ( x + 3 ) = 0
Using the Null factor law, make the expressions in each pair of parentheses equal 0.
x + 4 = 0
x = - 4
AND
x + 3 = 0
x = - 3
THEREFORE:
x = - 4 , x = - 3
For this question, we want to find out what 9 / 12 equals as a percent
or x / 100. Therefore, we have a proportion here and can say:
9/12 = x/100
Now, at this point, we can cross multiply to get:
900 = 12x
Now, divide both sides by 12 to get x alone and find that:
x = 75 <==== FINAL ANSWER
so 9 is 12% of 75!
I hope that helps you out! Please let me know if you have any other questions!
