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TheRedDevil18
- 408
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Homework Statement
ln(sec^-1(3x^2 +1))
Homework Equations
The Attempt at a Solution
1/sec-1(3x2+1) * 1/(3x2+1)(sqrt(3x2+1)2-1) * 6x
Is this correct ?, do I just simplify from here ?
TheRedDevil18 said:Homework Statement
ln(sec^-1(3x^2 +1))
Homework Equations
The Attempt at a Solution
1/sec-1(3x2+1) * 1/(3x2+1)(sqrt(3x2+1)2-1) * 6x
Is this correct ?, do I just simplify from here ?
Fredrik said:It looks wrong. There should be more trigonometric stuff in the result. How did you get that result? Do you know how to take the derivative of an inverse function: $$(f^{-1})'(x)=?$$
I didn't try to work it all out, but I'm thinking thatDick said:It's a little hard to interpret exactly without more parantheses, but it looks ok to me. What kind of 'more trignonometric' stuff are you looking for?
Fredrik said:I didn't try to work it all out, but I'm thinking that
$$\frac{d}{dx}\sec^{-1}(f(x))=(\sec^{-1})'(f(x))f'(x)=\frac{1}{\sec'(\sec^{-1}(f(x)))}f'(x)$$ and
$$\sec'(x)=\frac{d}{dx}\frac{1}{\cos x}=-\frac{1}{\cos^2x}(-\sin x).$$ So it looks like we get a big mess of "trigonometric stuff". But since you're both saying that he's right, I assume that I'm missing something.
The derivative of inverse trig functions is the rate of change of the inverse trigonometric function with respect to its input or argument. This is also known as the inverse trigonometric derivative.
To find the derivative of inverse trig functions, you can use the chain rule. This involves taking the derivative of the inverse trig function and multiplying it by the derivative of the inside function.
Sure, for example, if you want to find the derivative of arctan(x), you would use the chain rule and get 1/(1+x^2) as the derivative. Similarly, for arccos(x), the derivative would be -1/sqrt(1-x^2).
The common inverse trig functions and their derivatives are arctan(x), which has a derivative of 1/(1+x^2), arccos(x), with a derivative of -1/sqrt(1-x^2), and arcsin(x), which has a derivative of 1/sqrt(1-x^2).
Knowing the derivative of inverse trig functions is important because it allows us to find the slopes of curves that are defined by inverse trig functions. This is useful in many applications, especially in calculus and physics.