1 / 7

80 likes | 374 Vues

C2: Logarithms. Learning Objective: to be able to write an expression in logarithmic form. Logarithmic functions are the inverses of the exponential functions. The graph of a logarithmic function is the inverse of its exponential function (ie a reflection in the line y=x). Logarithms.

Télécharger la présentation
## C2: Logarithms

**An Image/Link below is provided (as is) to download presentation**
Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.
Content is provided to you AS IS for your information and personal use only.
Download presentation by click this link.
While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.
During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

**C2: Logarithms**Learning Objective: to be able to write an expression in logarithmic form**Logarithmic functions are the inverses of the exponential**functions. The graph of a logarithmic function is the inverse of its exponential function (ie a reflection in the line y=x)**Logarithms**Find p if p3 = 343. We can solve this equation by finding the cube root of 343: Now, consider the following equation: Find q if 3q = 343. We need to find the power of 3 that gives 343. One way to tackle this is by trial and improvement. Use the xy key on your calculator to find q to 2 decimal places.**Logarithms**This is defined as: y = logax ay= x The expressions and are interchangeable. y = logax To avoid using trial and improvement we need to define the poweryto which a given base a must be raised to equal a given number x. “y is equal to the logarithm, to the base a, of x” This can be written using the implication sign : y = loga x ay = x For example, 25 = 32 can be written in logarithmic form as: log2 32 = 5**Logarithms**y = loga x ay = x We have that: So: y = logaay Also: and Taking a log and raising to a power are inverse operations. For example: 2 6**Examples:**• Rewrite as a logarithm 54 = 625 • 54 = 625 • 4 = log5 625 • Find the value of log3 81 • log3 81 = x • 3x =81 • x = 4 (because 34 =81)**Task 1 :**• Exercise 3B & 3C

More Related