Simplify : sqrt -2 * sqrt - 8
http://img.photobucket.com/albums/v711/shannayanna476/M3FA_1.gif
How many real roots does this quadratic equation have that is represented by the graph above?
2007-09-29 10:07:17 · 2 answers · asked by gaby t 1 in Science & Mathematics ➔ Mathematics
√(-2)*√(-8)=i√(2)*i√(8)=i^2√(16)= -1*4= -4
2007-09-29 10:19:53 · answer #1 · answered by Anonymous · 0⤊ 0⤋
Yeah, the immodesty of the other answerer notwithstanding, he is right, as far as he dares go.
The graph shows a parabola, opening up, with a vertex above the x -axis. The real roots of an equation correspond with the x-intercepts of the graph. Since this graph never hits the x-axis, there are no real roots.
Here is an easy example: x^2 + 1 = y. Clearly, x^2 + 1 > 0 for all x, so there are no real roots. (The roots are +/- i = sqrt(-1)).
2007-09-29 19:07:08 · answer #2 · answered by Tony 7 · 0⤊ 0⤋