We discussed today that some quadratic equations can simply be solved using the square root (though with the specification that they still must include a plus/minus, since all* quadratic equations have two solutions). We also looked at an example of creating a quadratic equation from a word problem and solving it, taking care to ignore the answer that didn’t make sense in the context of the problem (the so-called extraneous solution). The notes can be found here, and your homework is HW 3.14 – Quadratic Word Problems. Check out this video for another example of a quadratic word problem involving area, and this video for more on solving equations with the square root.
*Okay, not all. Quadratics that factor to something like (x + 3)(x + 3) = 0 only have the one solution of x = -3.
Cumulative IXL Review Modules (newly added modules are in bold).
- J.5 – Solve a quadratic equation using the zero product property
- J.6 – Solve a quadratic equation by factoring
- J.9 – Solve a quadratic equation using the quadratic formula
- L.7 – Multiply radical expressions
- T.1 – Identify the direction a parabola opens (assigned 11/21 to 90)
- T.2 – Find the vertex of a parabola (assigned 11/21 to 90)
- T.4 – Find the axis of symmetry of a parabola (assigned 11/21 to 90)
- From Algebra 1
- BB.1 – Characteristics of quadratic functions (assigned 11/21 to 80)
- BB.5 – Solve a quadratic equation using square roots
- BB.10 – Solve a quadratic equation using the quadratic formula (assigned 12/6 to 80)