Solve each of the following equations. State the exact and approximate answers as
applicable. Use the solution method of your choice.
a) 4π₯^2 = 4π₯ + 15
To solve the equation 4π₯^2 = 4π₯ + 15, we can rearrange it to form a quadratic equation:
4π₯^2 - 4π₯ - 15 = 0
We can solve this equation by factoring or by using the quadratic formula. Let's use the quadratic formula:
The quadratic formula states that for an equation of the form ππ₯^2 + ππ₯ + π = 0, the solutions are given by:
π₯ = (-π Β± β(π^2 - 4ππ)) / (2π)
In our equation, π = 4, π = -4, and π = -15. Plugging these values into the quadratic formula, we get:
π₯ = (-(-4) Β± β((-4)^2 - 4(4)(-15))) / (2(4))
π₯ = (4 Β± β(16 + 240)) / 8
π₯ = (4 Β± β256) / 8
π₯ = (4 Β± 16) / 8
Taking the positive and negative values, we have:
π₯β = (4 + 16) / 8 = 20 / 8 = 2.5
π₯β = (4 - 16) / 8 = -12 / 8 = -1.5
So the solutions to the equation 4π₯^2 = 4π₯ + 15 are π₯ = 2.5 and π₯ = -1.5.