document.write( "Question 1192199: Variables x and y are such that, when e^y is plotted against x^2, a straight line graph passing through
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document.write( "the points (0.2, 1) and (0.5, 1.6) is obtained.
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document.write( "(i) Find the values of e^y when x = 0.
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document.write( "(ii) Express y in terms of x. \n" );
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Algebra.Com's Answer #849072 by CPhill(1959)![]() ![]() You can put this solution on YOUR website! Here's how to solve this problem:\r \n" ); document.write( "\n" ); document.write( "**(i) Find the values of e^y when x = 0:**\r \n" ); document.write( "\n" ); document.write( "1. **Recognize the linear relationship:** Since plotting *eʸ* against *x²* gives a straight line, we can express this relationship as:\r \n" ); document.write( "\n" ); document.write( " *eʸ = mx² + c*\r \n" ); document.write( "\n" ); document.write( " where *m* is the slope and *c* is the y-intercept.\r \n" ); document.write( "\n" ); document.write( "2. **Calculate the slope (m):** We are given two points on the line: (x², eʸ) = (0.2², 1) and (0.5², 1.6).\r \n" ); document.write( "\n" ); document.write( " *m = (change in eʸ) / (change in x²)* \n" ); document.write( " *m = (1.6 - 1) / (0.5² - 0.2²)* \n" ); document.write( " *m = 0.6 / (0.25 - 0.04)* \n" ); document.write( " *m = 0.6 / 0.21* \n" ); document.write( " *m = 20/7*\r \n" ); document.write( "\n" ); document.write( "3. **Calculate the y-intercept (c):** We can use either of the given points and the slope to find *c*. Let's use (0.2², 1):\r \n" ); document.write( "\n" ); document.write( " *1 = (20/7)(0.2²) + c* \n" ); document.write( " *1 = (20/7)(0.04) + c* \n" ); document.write( " *1 = 0.8/7 + c* \n" ); document.write( " *c = 1 - 0.8/7* \n" ); document.write( " *c = 6.2/7*\r \n" ); document.write( "\n" ); document.write( "4. **Find *eʸ* when *x = 0*:** Substitute *x = 0* into the equation *eʸ = mx² + c*:\r \n" ); document.write( "\n" ); document.write( " *eʸ = (20/7)(0²) + 6.2/7* \n" ); document.write( " *eʸ = 6.2/7*\r \n" ); document.write( "\n" ); document.write( " Therefore, when *x = 0*, *eʸ = 6.2/7* (approximately 0.886).\r \n" ); document.write( "\n" ); document.write( "**(ii) Express y in terms of x:**\r \n" ); document.write( "\n" ); document.write( "1. **We have the equation:** *eʸ = mx² + c*\r \n" ); document.write( "\n" ); document.write( "2. **Substitute the values of *m* and *c*:**\r \n" ); document.write( "\n" ); document.write( " *eʸ = (20/7)x² + 6.2/7*\r \n" ); document.write( "\n" ); document.write( "3. **Take the natural logarithm of both sides:**\r \n" ); document.write( "\n" ); document.write( " *ln(eʸ) = ln((20/7)x² + 6.2/7)*\r \n" ); document.write( "\n" ); document.write( "4. **Simplify:**\r \n" ); document.write( "\n" ); document.write( " *y = ln((20/7)x² + 6.2/7)*\r \n" ); document.write( "\n" ); document.write( "Therefore, *y = ln((20/7)x² + 6.2/7)*. \n" ); document.write( " \n" ); document.write( " |