Unformatted text preview: e that you can do the
quadratic formula work and so we won’t be showing that work. We will give the results of the
quadratic formula, we just won’t be showing the work.
Also, as we will see, we will need to get decimal answer to these and so as a general rule here we
will round all answers to 4 decimal places. Example 1 We are going to fence in a rectangular field and we know that for some reason we
want the field to have and enclosed area of 75 ft2. We also know that we want the width of the
field to be 3 feet longer than the length of the field. What are the dimensions of the field? Solution
So, we’ll let x be the length of the field and so we know that x + 3 will be the width of the field.
Now, we also know that area of a rectangle is length times width and so we know that, x ( x + 3) = 75 Now, this is a quadratic equation so let’s first write it in standard form. x 2 + 3 x = 75
x 2 + 3 x - 75 = 0
Using the quadratic formula gives, x= -3 ± 309
2 Now, at this point, we’ve got to deal with the fact that there are two solutions here and we only
want a single answer. So, let’s...
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This note was uploaded on 06/06/2012 for the course ICT 4 taught by Professor Mrvinh during the Spring '12 term at Hanoi University of Technology.
- Spring '12