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ConquerYOUR A LEVELS

Exponential Graph Intersections

The shown intersection PP lies to the left of 4. There, x−4<0x-4<0, so ∣x−4∣=4−x|x-4|=4-x. Equal outputs give 1+e2x=4−x1+e^{2x}=4-x.

For y=2+e−xy=2+e^{-x}, find the vertical-axis intercept and horizontal asymptote. Is the curve increasing or decreasing?

It decreases through (0,3) and approaches y=2y=2 from above as xx increases.

The input 3−x3-x must be positive, giving x<3x<3. Do not write ln⁡3−ln⁡x\ln3-\ln x: the subtraction is inside one log.

This is a rearrangement, not an explicit answer for xx, because xx still appears on both sides. Numerical solution methods come later.

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