Rui is a professional deep water free diver.His altitude (in meters relative to sea level), xxx seconds after diving, is modeled by:d(x)=\dfrac{1}{2}x^2 -10xd(x)= 21 x 2 −10xd, left parenthesis, x, right parenthesis, equals, start fraction, 1, divided by, 2, end fraction, x, start superscript, 2, end superscript, minus, 10, xWhat is the lowest altitude Rui will reach?
Accepted Solution
A:
the correct question is Rui is a professional deep water free diver. His altitude (in meters relative to sea level), xxx seconds after diving, is modeled by: d(x)=1/2x^2 -10x What is the lowest altitude Rui will reach?
we have that d(x)=(1/2)x² -10x
we know that the function is quadratic (a parabola) so the lowest altitude (depth) is the vertex
using a graph tool see the attached figure
the vertex is the point (10,-50) that means His altitude (in meters relative to sea level), 10 seconds after diving is 50 meters under the sea level
therefore the answer is the lowest altitude is 50 meters under the sea level