diff --git a/education/math/MATH1210 (calc 1)/Derivatives.md b/education/math/MATH1210 (calc 1)/Derivatives.md index dc85cdf..1d3fa69 100644 --- a/education/math/MATH1210 (calc 1)/Derivatives.md +++ b/education/math/MATH1210 (calc 1)/Derivatives.md @@ -28,7 +28,13 @@ The above formula can be used to find the *derivative*. This may also be referre $$ y - y_1 = m(x-x_1) $$ Given that $m = f'(a)$ and that $(x_1, y_1) = (a, f(a))$, you get the equation: $$ y - f(a) = f'(a)(x - a) $$ -As a more practical example, given an equation with a slope of $6$, +As a more practical example, given an equation with a slope of $6$ at the point $(-2, -4)$: +$$ y - (-4) = 6(x - -2)$$ +Solving for $y$ looks like this: +1. $y + 4 = 6(x + 2)$ +2. $y = 6(x + 2) - 4$ +3. $y = 6x + 12 - 4$ +4. $y = 6x + 8$ # Line Types ## Secant Line A **Secant Line** connects two points on a graph. @@ -123,9 +129,9 @@ $$ \dfrac{d}{dx} f(g(x)) = f'(g(x))*g'(x) $$ > Given the function $(x^2+3)^4$, find the derivative. Using the chain rule, the above function might be described as $f(g(x))$, where $f(x) = x^4$, and $g(x) = x^2 + 3)$. -6. First find the derivative of the outside function function ($f(x) = x^4$): +5. First find the derivative of the outside function function ($f(x) = x^4$): $$ \dfrac{d}{dx} (x^2 +3)^4 = 4(g(x))^3 ...$$ -7. Multiply that by the derivative of the inside function, $g(x)$, or $x^2 + 3$. +6. Multiply that by the derivative of the inside function, $g(x)$, or $x^2 + 3$. $$ \dfrac{d}{dx} (x^2 + 3)^4 = 4(x^2 + 3)^3 * (2x)$$ > Apply the chain rule to $x^4$ @@ -161,8 +167,8 @@ $$ \dfrac{d}{dx} \cot x = -\csc^2 x $$ - Given the equation $y = x^2$, $\dfrac{d}{dx} y = \dfrac{dy}{dx} = 2x$. Given these facts: -8. Let $y$ be some function of $x$ -9. $\dfrac{d}{dx} x = 1$ -10. $\dfrac{d}{dx} y = \dfrac{dy}{dx}$\ +7. Let $y$ be some function of $x$ +8. $\dfrac{d}{dx} x = 1$ +9. $\dfrac{d}{dx} y = \dfrac{dy}{dx}$\ ## Examples