document.write( "Question 1203202: This question below is part 2 of a question I had recently posted on algebra.com ( please see the previous question here on algebra.com about average rate of change (https://www.algebra.com/my/your-answer.mpl?question=1203157)\r
\n" );
document.write( "
\n" );
document.write( "\n" );
document.write( "
image upload
\r
\n" );
document.write( "\n" );
document.write( "A request: I haven't learned to solve this using derivatives so please solve using another method ( I use a different formula that doesn't require derivatives) \r
\n" );
document.write( "
\n" );
document.write( "\n" );
document.write( "Thank you in advance!
\n" );
document.write( " \n" );
document.write( "
Algebra.Com's Answer #838574 by math_tutor2020(3817)![]() ![]() ![]() You can put this solution on YOUR website! \n" ); document.write( "I'll use x in place of theta \n" ); document.write( "And use y in place of T\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Here are two resources to check out \n" ); document.write( "https://math.libretexts.org/Bookshelves/Calculus/Calculus_(OpenStax)/03%3A_Derivatives/3.05%3A_Derivatives_of_Trigonometric_Functions \n" ); document.write( "and \n" ); document.write( "https://math.libretexts.org/Courses/Mount_Royal_University/MATH_1200%3A_Calculus_for_Scientists_I/1%3A_Limit__and_Continuity_of_Functions/1.7%3A_Limit_of__Trigonometric_functions\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "The first link talks about the derivative of trig functions. \n" ); document.write( "What we're interested in mainly is that \n" ); document.write( "derivative of sine = cosine \n" ); document.write( "or in terms of symbols \n" ); document.write( "d/dx[ sin(x) ] = cos(x)\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Rephrased another way \n" ); document.write( "y = sin(x) leads to dy/dx = cos(x)\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "The second link is a supplement to explain two important trig limit identities.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "If y = (2V/g)*sin(x) then dy/dx = (2V/g)*cos(x) \n" ); document.write( "The (2V/g) portion is a constant.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Plug in x = pi/6 to get: \n" ); document.write( "dy/dx = (2V/g)*cos(x) \n" ); document.write( "dy/dx = (2V/g)*cos(pi/6) \n" ); document.write( "dy/dx = (2V/g)*sqrt(3)/2 \n" ); document.write( "dy/dx = (V/g)*sqrt(3)\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Use the unit circle to determine that cos(pi/6) = sqrt(3)/2\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Answer: The instantaneous rate of change is (V/g)*sqrt(3) when theta = pi/6\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "-------------------\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Edit: \r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "I just realized you wrote that you haven't learned derivatives just yet. \n" ); document.write( "Another approach would be to find the average rate of change over the interval [pi/6, pi/4] as done so in this link \n" ); document.write( "https://www.algebra.com/algebra/homework/word/misc/Miscellaneous_Word_Problems.faq.question.1203157.html\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "pi/6 = 0.523599 approximately \n" ); document.write( "pi/4 = 0.785398 approximately\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "So the interval [pi/6, pi/4] is approximately [0.523599, 0.785398]\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Then shrink that interval down to something like [0.523599, 0.7] then to [0.523599, 0.6] \n" ); document.write( "The idea is to keep shrinking the interval such that pi/6 = 0.523599 is kept constant as the left endpoint. Only the right endpoint will move closer and closer to pi/6\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "As this right side approaches pi/6, the average rate of change will approach the instantaneous rate of change. \n" ); document.write( " \n" ); document.write( " |