1. **Problem statement:**
We are given the function $$y = \frac{1}{2x^2} + 3x$$ for $$-1 \leq x \leq 3$$.
(i) Estimate the gradient of the curve at $$x=0.5$$ by drawing a tangent.
(ii) Estimate the solution(s) of the equation $$\frac{1}{2x^2} + 3x = 2$$ using the graph.
(iii) Estimate the solution(s) of the equation $$\frac{1}{2x^2} = 7 - 4x$$ by drawing a suitable line on the grid.
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2. **Formula and rules:**
- The gradient of a curve at a point is the slope of the tangent line at that point.
- To find the gradient at $$x=0.5$$, we estimate the slope of the tangent line drawn at that point.
- To solve equations graphically, find the x-values where the curve intersects the horizontal line representing the constant on the right side.
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3. **Step (i): Estimate gradient at $$x=0.5$$**
- Draw a tangent line at $$x=0.5$$ on the graph.
- Estimate two points on the tangent line, say $$(x_1,y_1)$$ and $$(x_2,y_2)$$.
- Calculate gradient $$m = \frac{y_2 - y_1}{x_2 - x_1}$$.
- From the graph, the tangent appears to rise about 4 units when moving 1 unit right, so gradient $$\approx 4$$.
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4. **Step (ii): Estimate solution of $$\frac{1}{2x^2} + 3x = 2$$**
- On the graph, find where $$y = \frac{1}{2x^2} + 3x$$ intersects the horizontal line $$y=2$$.
- From the graph, this occurs near $$x \approx 0.3$$.
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5. **Step (iii): Estimate solutions of $$\frac{1}{2x^2} = 7 - 4x$$**
- Rewrite as $$y_1 = \frac{1}{2x^2}$$ and $$y_2 = 7 - 4x$$.
- Draw the line $$y = 7 - 4x$$ on the graph.
- Find intersection points of $$y_1$$ and $$y_2$$.
- From the graph, intersections appear near $$x \approx 0.5$$ and $$x \approx 1.5$$.
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**Final answers:**
(i) Gradient at $$x=0.5$$ is approximately $$4$$.
(ii) Solution to $$\frac{1}{2x^2} + 3x = 2$$ is approximately $$x=0.3$$.
(iii) Solutions to $$\frac{1}{2x^2} = 7 - 4x$$ are approximately $$x=0.5$$ and $$x=1.5$$.
Curve Gradient Solutions
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