LEARN · EXPLAIN · REVISE

Which point is the vertex of this graph?

Read the idea, work independently, then explain what changed.

TOPIC 01

Quadratic equations and functions

The graph opens downwards and its maximum is 7. The coefficient −3 is not a coordinate of the vertex.

PREDICT → MOVE → EXPLAIN

Before moving a slider, predict the opening, vertex and intercepts. Then compare the graph with your prediction.

Use one hint at a time. A correction explains what changed, not just the final answer.

01 / Foundation#Your turn

y=-3(x+2)^2+7

Working and explanation

BUILD THE REASONING

Hint 1

Compare with the vertex form a(x − h)² + k.

Hint 2

Find the x-value that makes x + 2 equal to zero.

Worked solution

Rewrite the bracket to show h.
$x+2=x-(-2)$
Read the vertex. The negative leading coefficient changes the opening direction.
$(h,k)=(-2,7)$

B: the vertex is (−2, 7).

Checks and common pitfalls: The graph opens downwards and its maximum is 7. The coefficient −3 is not a coordinate of the vertex.

Think first. Reveal a hint when the class is ready.