User:
• Matrices
• Algebra
• Geometry
• Funciones
• Trigonometry
• Coordinate geometry
• Combinatorics
 Suma y resta Producto por escalar Producto Inversa
 Monomials Polynomials Special products Equations Quadratic equations Radical expressions Systems of equations Sequences and series Inner product Exponential equations Matrices Determinants Inverse of a matrix Logarithmic equations Systems of 3 variables equations
 2-D Shapes Areas Pythagorean Theorem Distances
 Graphs Definition of slope Positive or negative slope Determine slope of a line Ecuación de una recta Equation of a line (from graph) Quadratic function Posición relativa de dos rectas Asymptotes Limits Distancias Continuity and discontinuities
 Sine Cosine Tangent Cosecant Secant Cotangent Trigonometric identities Law of cosines Law of sines
 Ecuación de una recta Posición relativa de dos rectas Distancias Angles in space Inner product

 Slopes of parallel and perpendicular lines Parallel lines have the same slope. Line a constains the points (-1,4) and (4,6). Line b contains the points (5,2) and (-3,-3). Are the two lines parallel? Step 1 is to calculate the slope for Line a. The formula for the slope of a line is: $\frac{y_2-y_1}{x_2-x_1}$ $\frac{y_2-y_1}{x_2-x_1}=\frac{6-4}{4-(-1)}=\frac{2}{5}$ Step 2 is to calculate the slope for Line b. The formula for the slope of a line is: $\frac{y_2-y_1}{x_2-x_1}$ $\frac{y_2-y_1}{x_2-x_1}=\frac{-3-2}{-3-5}=\frac{-5}{-8}=\frac{5}{8}$ Parallel lines have the same slope. Since the slope of Line a does not equal the slope of Line b, the lines cannot be parallel. Two lines are perpendicular if the slope of one line (m) equals the negative reciprocal of the other $(\frac{-1}{m})$ Line a constains the points (-2,-2) and (6,4). Line b contains the points (0,4) and (3,0). Are the two lines perpendicular? Step 1 is to calculate the slope for Line a. The formula for the slope of a line is: $\frac{y_2-y_1}{x_2-x_1}$ $\frac{y_2-y_1}{x_2-x_1}=\frac{4-(-2)}{6-(-2)}=\frac{4+2}{6+2}=\frac{6}{8}=\frac{3}{4}$ Step 2 is to calculate the slope for Line b. The formula for the slope of a line is: $\frac{y_2-y_1}{x_2-x_1}$ $\frac{y_2-y_1}{x_2-x_1}=\frac{0-4}{3-0}=\frac{-4}{3}$ Two lines are perpendicular if the slope of one line (m) equals the negative reciprocal of the other $(\frac{-1}{m})$. Since the slope of Line a is 3/4 and the slope of Line b is -4/3, the lines are perpendicular.