PRECALCULUS)HONORS)TEST)REVIEW))
3.4—3.5!
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Solve!for!x.!!When!necessary,!approximate!your!result!to!three!decimal!places.!
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1. 8 x = 512 !
2.!! log 4 x = 2 !
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3. e4 x = e x
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5. 2 ln 4x = 15 !
4.!! 2 x + 13 = 35 !
6.!! ln x + 1 = 2 !
7. log 8 (x − 1) = log 8 (x − 2) − log 8 (x + 2) !
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8. Find!the!exponential!model! y = ae bx !that!passes!through!the!points! (0, 2), (4, 3) .!
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9. You&deposit&$7550&in&an&account&that&pays&7.25%&interest,&compounded&
continuously.&&How&long&will&it&take&for&the&money&to&triple?&
10. The&halfDlife&of&radioactive&uranium& II (234 U ) &is&about&250,000&years.&&What&percent&
of&a&present&amount&of&radioactive&uranium&II&will&remain&after&5000&years?&
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11. A&species&of&bat&is&in&danger&of&becoming&extinct.&&Five&years&ago,&the&total&population&
of&the&species&was&2000.&&Two&years&ago,&the&total&population&of&the&species&was&
1400.&&What&was&the&total&population&of&the&species&one&year&ago?&
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12. The&test&scores&for&a&biology&test&follow&a&normal&distribution&modeled&by&&
y = 0.0499e
test&score.&
−( x − 71)2
128
,
40 ≤ x ≤ 100 &where&x&is&the&test&score.&&Estimate&the&average&