Graphing Tangents to a Quadratic Curve

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SUMMARY

The discussion focuses on finding the equation of the tangent line to the quadratic curve defined by the function y = 3 - x² at the point (-1, 2). The slope of the tangent is calculated to be 2, leading to the tangent line equation y = 2x + 4. Participants clarify how to graph the tangent line alongside the quadratic curve, emphasizing that the tangent crosses the x-axis when y = 0, which occurs at x = -2.

PREREQUISITES
  • Understanding of quadratic functions and their graphs
  • Knowledge of derivatives and slope calculation
  • Familiarity with the point-slope form of a linear equation
  • Basic graphing skills for plotting curves and lines
NEXT STEPS
  • Study the concept of derivatives in calculus for slope determination
  • Learn how to graph quadratic functions using vertex and intercepts
  • Explore the point-slope form of linear equations in detail
  • Practice graphing tangents to various curves for better understanding
USEFUL FOR

Students studying calculus, mathematics educators, and anyone interested in graphing quadratic functions and their tangents.

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Homework Statement


Find an equation for the tangent to the curve at the given point. Then sketch the curve and tangent together

Homework Equations


y=3-x^2 (-1,2)

The Attempt at a Solution



slope =

f(x + h) + f(x) / h

f(-1 + h) + 2 / h

3- (-x + h)^2 + 2 / h

3 - 1 + 2h + H^2 + 2 / h

2h + h^2 / h

= 2 + h
= 2

slope is 2

y - y1 = m(x - x1)

y - 2 = 2 (x + 1)
y = 2x + 4 = equation Ok so I have no idea how to graph a tangent, can someone tell me how you graph this? I know how to sketch the graph 3- x^2 since it is a ^2 function it is u shaped, flipped on the x-axis moved up three on the y. I know the tangent obviously passes through -1, 2 but how do I graph the rest? I know y intercept for tangent is 4, but where does it pass through x at? I am a little rusty
 
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Do you mean where does it cross the x-axis? It does that when y=0 in the equation y=2x+4. Solve for x. You are rusty. It's just graphing a straight line.
 

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