Tutoring math, you see trig equations. The tutor mentions some top-down ideas. Considering the equation sinx=K, for K ε Reals sinx = sin(180°-x), 0≤x<90°. Therefore, if the equation has a solution θ between 0 and 90°, it will typically have …
Tutoring math, inverses come up. The tutor begins about them. Simply put, an inverse takes (x,y) and makes it (y,x). If f(x) yields y, then f-1(y) yields x. To get the inverse algebraically, one interchanges x with y. For instance, …
Tutoring math, factoring is a typical topic. The tutor mentions a novelty. In this post, x^n means xn Sometimes, one can factor third degree polynomials of the form ax^3 +bx^2 +cx + d without using the remainder theorem, synthetic division, …
Tutoring math, word problems come up. The tutor gives an example of “let” statements. Problem: A 207cm rope is cut in two pieces, one 15cm longer than the other. How long is each piece? Solution: “let” statements are used to …
Tutoring math, you see exponential growth and decay. The tutor mentions an equation from a half life. Example: a specimen loses half activity every 45 days. Find a equation for it. Answer: The equation will be of the form P …
Exponents and logs: a decay equation from a half life. Read more »
Tutoring math, percents come up. The tutor mentions a couple of quick methods. In math, “of” typically means “multiply:” thus, 37% of 165 is (37/100)x165 = 61.05. On the other hand, if the total isn’t known, but a certain percent …
Tutoring math, factors are important to understand. The tutor gives a briefing. A factor, in math, means a number that divides into another with no remainder. For instance, 4 is a factor of 12 but 5 isn’t. When you break …
Tutoring math, details can be important. The tutor mentions negative signs in front of exponential expressions. For situations where superscripts aren’t available, exponents are sometimes indicated with a ^ sign. Therefore, 3^4 = 3*3*3*3 = 81. Today’s post isn’t about …
Exponential expressions: coefficients: negative signs Read more »
Tutoring math, exponents may appear as early as middle school. The tutor gives an idea. An exponent, in most textbooks, is signified by a superscript such as 35. This means “3 exponent 5” which is 3x3x3x3x3 = 243. Typically, the …
Tutoring math, everyday problems need easy methods when possible. The tutor mentions one. Let’s imagine a consumer buys an item with sticker price $44, subject to 15% discount, then 12% tax. What is the final amount they will pay? One …