Arithmetic Sequence Problem Solving, Exercises of Mathematics

Download Arithmetic Sequence Problem Solving and more Exercises Mathematics in PDF only on Docsity! Problem: 5. True or False: The explicit formula from the sequence -1, 3, 7, 11, … is an=5an−4. Answer: False The sequence is -1, 3, 7, 11, … a1=−1, a2=3, a3=7, a4=11. The explicit formula is an=5an−4. So: When a1=−1 −1=5 (−1 )−4 (substitute the value of a1) −1=−5−4 (5 times -1 is -5) −1=−9 (-5 minus 4 is -9) −1≠−9 (-1(a1) is not equal to -9 hence the answer is false.) You can further try to test when a2=3, a3=7, a4=11 but it is not necessary since it is already false when a1=−1.