Honors Analysis Section 6.3: Special Right Triangles Q Problems Q1.) Simplify: 4−2 Q3.) Simplify: √25𝑎4 𝑏 6 1 3 Q2.) Simplify: 125 Q5.) Simplify: √𝑥 2 + 10𝑥 + 25. If you are stuck, 3 Q4.) √27𝑎6 𝑏 3 Q6.) Rationalize the denominator: 5 4−√6 think about what a square root means, and then try factoring the expression. Q7.) Determine the volume of a cylinder with a height of Q8.) Calculate the lateral surface area of the cylinder in Q7. 8 cm and a 5 cm radius. Q9.) Determine the altitude of a square pyramid with a 10 x 10 base and a slant height of 13 units. Q10.) What is the volume of the pyramid in Q9? 1.) Divide a square with dimensions x by x into halves along the diagonal to form 45-45-90 triangles. Then use the Pythagorean Theorem to derive the relationships between the sides. 2.) Draw an equilateral triangle with side lengths of 2x. Split the triangle into two 30-60-90 triangles using an altitude. Then use the Pythagorean Theorem to derive the relationships between the sides. 3.) Determine the lengths of the missing sides of the 45-45-90 triangles shown: 4.) Determine the lengths of the missing sides of the 30-60-90 triangles shown: 5.) Determine each missing side length. Write all values in simplified radical form. Rationalize all denominators. 6.) Find the area of an equilateral triangle with 4 cm sides. 7.) What is the area of an isosceles triangle with a base length of 18 ft and a vertex angle measuring 120º? 8.) An equilateral triangle with a 24 cm altitude has what area? 9.) One of the angles of a rhombus measures 120º. If the perimeter is 24 in, find the length of each diagonal. 10.) What is the slope of a line passing through the origin that forms a 30º angle with the x-axis? 11.) What is the slope of a line passing through the origin that forms a 60º angle with the x-axis? 12.) Calculate the area of the isosceles trapezoid: 13.) Determine, to the nearest tenth, the perimeter of the trapezoid. 14.) The “span” of a hexagon is the distance between opposite sides. Determine the span of the regular hexagon shown: 15.) Determine the perimeter and the span of the regular octagon shown. (Hint: Calculate angle measures within the octagon.) 16.) 17.) 18.) 19.) 20.) Write an algebraic proof demonstrating that an equilateral triangle with sides of length s has an 21. A) What is the length of the diagonal of a 5 x 5 x 5 cube? area of 𝑠2 √3 4 B) What is the length of the diagonal of an x by x by x cube? Honors Analysis Enrichment Topic #1B: Imaginary Numbers Powers of i: You already know that the imaginary number i is defined as √−1, and that as a result, i2 = -1. Other powers of i can also be determined by writing the numbers using values that are already known. For example, i3 can be written as 𝑖 ∙ 𝑖 2 . Since i2 = -1, 𝑖 ∙ 𝑖 2 simplifies down to 𝑖 ∙ −1, or - i. Likewise, i4 can be written as the product 𝑖 2 ∙ 𝑖 2 , which is the same as −1 ∙ −1, which means that i4 = 1. The fact that i4 = 1 is very useful, because all additional powers of i can be written as the product of i4 and a second value, which makes for easy simplifications. For example, 𝑖 5 = 𝑖 4 ∙ 𝑖. Since i4 = 1, the expression simplifies down to i. 𝑖 6 = 𝑖 4 ∙ 𝑖 2 = 1 ∙ −1 = −1. Look at the following list of powers of i, and look for a pattern: 𝑖1 = 𝒊 𝑖 2 = −𝟏 𝑖 3 = −𝒊 𝑖4 = 𝟏 𝑖5 = 𝑖4 ∙ 𝑖 = 𝒊 𝑖 6 = 𝑖 4 ∙ 𝑖 2 = −𝟏 𝑖 7 = 𝑖 4 ∙ 𝑖 3 = −𝒊 𝑖8 = 𝑖4 ∙ 𝑖4 = 𝟏 𝑖 9 = 𝑖 4 ∙ 𝑖 4 ∙ 𝑖1 = 𝒊 𝑖 10 = 𝑖 4 ∙ 𝑖 4 ∙ 𝑖 2 = −𝟏 As you might notice, the powers of i cycle from i to -1 to –I to 1. So to calculate any power of i, the key is to cancel all powers of i4. So for example, 𝑖 22 = 𝑖 4 ∙ 𝑖 4 ∙ 𝑖 4 ∙ 𝑖 4 ∙ 𝑖 4 ∙ 𝑖 2 = −1. Use this pattern to calculate the following powers of i: E1.) 𝑖 11 E2.) 𝑖 17 E3.) 𝑖 31 E4.) 𝑖 101 E5.) 𝑖 120 E6.) (2𝑖)6 Division of Complex Numbers Similar to rules for radicals, it is considered bad form to have an imaginary number in the denominator of a fraction. Similar to radicals, an i in the denominator can be squared to result in a real number value, but the numerator must also 4 be multiplied by the same value. So 𝑖 can be written in a more standard form by multiplying the numerator and 4 𝑖 4𝑖 denominator by i: ∙ = = −4𝑖. If the denominator involves addition or subtraction, the numerator AND 𝑖 𝑖 −1 denominator can be multiplied by the conjugate of the complex number – that is, the complex number with the sign of the imaginary part switched. Example: 5 2+𝑖 → 5 2−𝑖 ∙ 2+𝑖 2−𝑖 5(2−𝑖) = (2+𝑖)(2−𝑖) = 10−5𝑖 4−2𝑖+2𝑖−𝑖 2 E7.) What is the conjugate of 3 + 2i? E9.) Divide: 6 3−𝑖 E10.) Divide: = 10−5𝑖 4−𝑖 2 = 10−5𝑖 4−−1 = 10−5𝑖 5 = 2−𝑖 1 =2−𝑖 E8.) What is the product of 4 – 5i and its conjugate? 4 5+2𝑖 E11.) Divide: 3+4𝑖 1−2𝑖