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Find the equation of the tangent line to a circle at a given point.
March 2, 2025
The equation of the tangent line to the circle (x-3)^2 + (y-2)^2 = 25 at the point (-1, 5) is 4x - 3y + 19 = 0.
Problems involving sets, functions, and probability.
February 27, 2025
The solution finds the symmetric difference between two sets derived from inverse functions, demonstrating the application of set theory and function operations. It also proves a set identity involving unions and intersections of sets, and calculates derivatives of composite functions using the chain rule. Finally, it calculates probabilities of events involving coin tosses and dice rolls, and determines the probability of having 53 Sundays or Mondays in a leap year.
Calculate the determinant of a 3x3 matrix with variables x, y, and z.
February 23, 2025
The determinant is evaluated by splitting it into two parts, factoring out terms, and using the Vandermonde determinant formula. The final result is expressed as a product of factors involving x, y, and z, and a term (1-xyz).
Find the missing side length of a rectangle.
February 19, 2025
The area of the unknown rectangle (A4) is calculated to be 6 square meters by using the given areas of the other rectangles and the relationships between their dimensions.
Solving a system of two linear equations
February 19, 2025
The system of equations 6^x + 6^y = 42 and x + y = 3 has two solutions: (x, y) = (2, 1) and (x, y) = (1, 2).
Confidence Interval for Variance of Bolt Diameters
February 11, 2025
The solution calculates confidence intervals for the variance and mean of bolt diameters, demonstrating how reducing the confidence level results in a narrower confidence interval for the mean.
Confidence Interval for the Weight of Cement Bags
February 11, 2025
The solution calculates 95% confidence intervals for a population mean using both the t-distribution (when population variance is unknown) and the z-distribution (when population variance is known). It also discusses how increasing the confidence level results in a wider confidence interval.
Calculate the confidence interval for the expected value
February 11, 2025
The 95% confidence interval for the population mean is [66.04, 69.96], calculated using a sample mean of 68, a known variance of 22, and a sample size of 22. The minimum sample size needed to achieve a maximum confidence interval width of 1 is 338.
Calculate the confidence interval for a sample mean.
February 11, 2025
The 95% confidence interval for the population mean is approximately [13.984, 14.416]
Calculate the confidence interval for the population mean.
February 11, 2025
The provided text details step-by-step calculations for confidence intervals of means and variances, along with sample size determination, under different scenarios (known and unknown population standard deviation). The solutions involve using z-scores, t-scores, and chi-squared values to construct intervals for population parameters.