Hey. I've taken quite a few tests this past weekend and I'm learning many new tricks. I came across problems like these and i just skipped them. Can someone help.
1. f(x) = -4x+2, then f^-1(10) = _____?
Answer is -2.
2. If f(x) = -x+3, then f^-1 (5) =______?
Answer is -2.
3. The 17th term of the arithmetic sequence 7,8,11,14... is________?
1. Because it is inverse, set -4x+2=10 and solve and obtain x=-2 2. Same thing, set -x+3=5, solving yields x=-2 3. in an arithmetic sequence, a, a+b, a+2b, a+3b..., the nth term is a+(n-1)b 4. there are 2 digits after the decimal, so in your base 10 fraction the denominator is 5^2=25, and for the numerator, just convert 41base5 to base 10--> 21, so the fraction in base 10 is 21/25=.84. Another example, change .123 in base 6 to base 10: because there's 3 digits after the decimal, so the denom is 6^3=216, and for numerator, convert 123base6 to base 10 and obtain 51, and put 51 over 216, reduce to 17/72.
