document.write( "Question 350476: Please help me solve this equation: Consider the function \"+f%28x%29=+root%283%2Cx%29+\", \"+1%3C=x%3C=8+\". \r
\n" ); document.write( "\n" ); document.write( "a) Find the average value of f on the interval [1, 8].\r
\n" ); document.write( "\n" ); document.write( "b) Find c such that fave. = f (c).\r
\n" ); document.write( "\n" ); document.write( "c) Sketch the graph of f and a rectangle whose area is the same as the area under
\n" ); document.write( "the graph of f .
\n" ); document.write( "

Algebra.Com's Answer #250534 by jsmallt9(3758)\"\" \"About 
You can put this solution on YOUR website!
Please help me solve this equation: Consider the function \"+f%28x%29=+root%283%2Cx%29+\", \"+1%3C=x%3C=8+\". \r
\n" ); document.write( "\n" ); document.write( "a) Find the average value of f on the interval [1, 8].
\n" ); document.write( "For the average value on this interval you will use:
\n" ); document.write( "\"%28int%28root%283%2C+x%29%2C+dx%2C+1%2C+8%29%29%2F%288-1%29\"
\n" ); document.write( "Writing the radcial in fractional exponent form will probably help with finding the integral:
\n" ); document.write( "\"%28int%28x%5E%281%2F3%29%2C+dx%2C+1%2C+8%29%29%2F%288-1%29\"
\n" ); document.write( "The indefinite integral of \"x%5E%281%2F3%29dx\" is \"x%5E%284%2F3%29%2F%284%2F3%29+%2B+C+=+%283x%5E%284%2F3%29%29%2F4+%2B+C\". The definite integral, from 1 to 8, will be:
\n" ); document.write( "\"%283%288%29%5E%284%2F3%29%29%2F4+-+%283%281%29%5E%284%2F3%29%29%2F4\"
\n" ); document.write( "\"8%5E%284%2F3%29+=+8%5E%28%281%2F3%29%2A4%29+=+%288%5E%281%2F3%29%29%5E4+=+2%5E4+=+16\". So now we have
\n" ); document.write( "\"%283%2816%29%29%2F4+-+3%2F4\"
\n" ); document.write( "\"48%2F4+-+3%2F4\"
\n" ); document.write( "\"45%2F4\"
\n" ); document.write( "Now the average value is:
\n" ); document.write( "\"%2845%2F4%29%2F7+=+45%2F28\"

\n" ); document.write( "b) Find c such that fave. = f (c).
\n" ); document.write( "So we solve:
\n" ); document.write( "\"f%28c%29+=+45%2F28\"
\n" ); document.write( "\"root%283%2C+c%29+=+45%2F28\"
\n" ); document.write( "Cube both sides:
\n" ); document.write( "\"c+=+91125%2F21952\"

\n" ); document.write( "c) Sketch the graph of f and a rectangle whose area is the same as the area under the graph of f.
\n" ); document.write( "The graph of f (without the limited domain) looks like:
\n" ); document.write( "\"graph%28400%2C+400%2C+-1%2C+11%2C+-1%2C+5%2C+x%5E%281%2F3%29%29\"
\n" ); document.write( "Note:
  • Truncate this graph so that only the part between x = 1 and x = 8 shows.
  • I think the intention is for the graph of the rectangle to be on the same graph. Specifically, the bottom of the rectangle should be the on the x axis between 1 and 8 and the sides will be 45/28 in height extending up from the x axis (at x = 1 and x = 8). If done well, the top of the rectangle should intersect the graph of f at x = c = 91125/21952 (which is approximately 4.15)
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