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Find the derivative of each function using the limit definition.\newlinea. \newlinef(x)=x2+3x5f(x)=x^{2}+3x-5

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Q. Find the derivative of each function using the limit definition.\newlinea. \newlinef(x)=x2+3x5f(x)=x^{2}+3x-5
  1. Write Limit Definition: Write down the limit definition of the derivative.\newlineThe derivative of a function f(x)f(x) at a point xx is given by the limit as hh approaches 00 of the difference quotient: f(x)=limh0f(x+h)f(x)hf'(x) = \lim_{h \to 0} \frac{f(x+h) - f(x)}{h}.
  2. Apply to Function: Apply the limit definition to the function f(x)=x2+3x5f(x) = x^2 + 3x - 5. We need to calculate the limit as hh approaches 00 of the expression: (f(x+h)f(x))/h=((x+h)2+3(x+h)5(x2+3x5))/h(f(x+h) - f(x))/h = ((x+h)^2 + 3(x+h) - 5 - (x^2 + 3x - 5))/h.
  3. Expand Numerator: Expand the numerator of the difference quotient.\newlineExpand (x+h)2(x+h)^2 and 3(x+h)3(x+h) in the numerator to get: (x2+2xh+h2+3x+3h5x23x+5)/h(x^2 + 2xh + h^2 + 3x + 3h - 5 - x^2 - 3x + 5)/h.
  4. Simplify Numerator: Simplify the numerator by canceling out like terms. The terms x2x^2, 3x3x, and 5-5 cancel out with x2-x^2, 3x-3x, and +5+5, respectively, leaving us with: (2xh+h2+3h)/h(2xh + h^2 + 3h)/h.
  5. Factor Out hh: Factor out hh from the numerator.\newlineFactor hh from each term in the numerator to get: h(2x+h+3)h\frac{h(2x + h + 3)}{h}.
  6. Cancel hh: Simplify the difference quotient by canceling hh. Cancel hh in the numerator and denominator to get: 2x+h+32x + h + 3.
  7. Take Limit: Take the limit as hh approaches 00. Now we need to find the limit of 2x+h+32x + h + 3 as hh approaches 00, which is simply 2x+32x + 3 since the term involving hh vanishes.
  8. Write Final Derivative: Write down the final derivative.\newlineThe derivative of the function f(x)=x2+3x5f(x) = x^2 + 3x - 5 is f(x)=2x+3f'(x) = 2x + 3.

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