Unit 4B Flashcard Review

Front

What number should be added to complete the square for the expression a^2 + 10a?

Back

49

Front

What is the first step to solving the equation a^2 + 10a + 21 = 0 by completing the square?

Back

Subtract the 21.

Front

When do you use the plus or minus symbol (±) in solving equations?

Back

After taking the square root of both sides.

Front

Find the zeros of the equation (x+10)(x-2) = 0.

Back

-10 and 2.

Front

Solve the quadratic equation n^2 - 5 = -4.

Back

n = ±1.

Front

What is the formula for completing the square?

Back

(x + b/2)^2 = x^2 + bx + (b/2)^2.

Front

What does it mean to 'complete the square'?

Back

To transform a quadratic equation into a perfect square trinomial.

Front

What is the vertex form of a quadratic equation?

Back

y = a(x - h)^2 + k, where (h, k) is the vertex.

Front

How do you find the vertex of a parabola given in standard form?

Back

Use the formula h = -b/(2a) to find the x-coordinate.

Front

What is the significance of the discriminant in a quadratic equation?

Back

It determines the nature of the roots: positive (two real roots), zero (one real root), negative (no real roots).