Algebra.Com's Answer #519376 by Alan3354(69443)![\"\"](\"/images/stars/stars-13.gif\")  
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Solve using derivatives - A dart is shot straight up from 1.5 metres above ground level. The distance (d), in metres, the dart is above the ground at time (t), in seconds is: \r
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document.write( "1) What is the maximum height the dart reaches? I think this is 21.92 m
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document.write( "Already answered.
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document.write( "2) for how many seconds is the dart in the air?
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document.write( "From t = 0 until d(t) = 0 at impact.
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document.write( " | Solved by pluggable solver: SOLVE quadratic equation (work shown, graph etc) | \n" );
document.write( "Quadratic equation  (in our case  ) has the following solutons:
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document.write( " For these solutions to exist, the discriminant  should not be a negative number.
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document.write( " First, we need to compute the discriminant :  .
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document.write( " Discriminant d=429.4 is greater than zero. That means that there are two solutions:  .
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document.write( " Quadratic expression  can be factored:
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document.write( " Again, the answer is: -0.0736703080011585, 4.15530296106238.\n" );
document.write( "Here's your graph:
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document.write( "Ignore the negative solution.
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document.write( "t =~ 4.155 seconds \n" );
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