Someone help me out really quick
1 answer:
Answer:
Roots: 3.746 and -13.746
Vertex: (-5, 153)
Step-by-step explanation:
- The roots of the quadratic equation y = ax² + bx + c, are the values of x at y = 0
- Its vertex is (h, k), where, h =
, and k is the value of y at x = h
Let us use these facts to solve the question
∵ y = -2x² - 20x + 103
→ Compare it by the form of the equation above
∴ a = -2, b = -20, and c = 103
→ To find its roots equate y by 0
∵ 0 = -2x² - 20x + 103
→ Use your calculator to find the values of x
∴ x = 3.746427842 and x = -13.74642784
→ Round them to 3 decimal places
∴ x = 3.746 and x = -13.746
∴ Roots: 3.746 and -13.746
→ To find its vertex use the rule of h above
∵ a = -2 and b = -20
∵ h = =
∴ h = -5
→ To find k substitute y by k and x by -10 in the equation
∵ k = -2(-5)² - 20(-5) + 103
∴ k = -2(25) + 100 + 103
∴ k = -50 + 100 + 103
∴ k = 153
∴ The vertex of the quadratic is (-5, 153)
∴ Vertex: (-5, 153)
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<h2>Perfect Squares</h2>
Perfect square formula/rules:
Trinomials are often organized like .
The <em>b</em> value in this case is <em>c</em>, and it will always equal the square of half of the <em>b</em> value.
- Perfect square trinomial:
- or
We're given:
In a trinomial, we're given the and
values. <em>a</em> in this case is 1 and <em>b</em> in this case is 4. To find the third value by dividing 4 by 2 and squaring the quotient:
- 4 ÷ 2 = 2
- 2² = 4
Therefore, the term that we can add is + 4.
To write this as the square of a bracketed expression, we can follow the rule :