Q. Determine the following limit in simplest form. If the limit is infinite, state that the limit does not exist (DNE).x→∞lim3x+5x225x4−28x2Answer:
Simplify Expression: To find the limit of the given function as x approaches infinity, we should first simplify the expression by dividing the numerator and the denominator by the highest power of x in the denominator, which is x2.
Divide by x2: Divide both the numerator and the denominator by x2:x→∞lim(3x+5x225x4−28x2)=x→∞lim⎝⎛x23x+x25x2x225x4−x228x2⎠⎞
Approaching Infinity: As \(x approaches infinity, the terms x3 and −x228 will approach 0. So we can simplify the expression further:x→∞lim(x3+525x2−28)=x→∞lim(525x2)
Square Root Simplification: The square root of 25x2 is 5x (since x is approaching infinity, we consider only the positive square root):x→∞lim(525x2)=x→∞lim(55x)
Cancel Common Factor: Simplify the expression by canceling out the common factor of 5:x→∞lim(55x)=x→∞limx
Limit as x approaches Infinity: The limit of x as x approaches infinity is infinity: limx→∞x=∞
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