Hey there! Sign in to join this conversationNew here? Join for free
x Turn on thread page Beta
    • Thread Starter
    Offline

    0
    ReputationRep:
    Has anyone have a clue how to solve this?

    calculate the value of y for which 2 log 3 y - log 3 (y+4) = 2

    Thanks in advance
    Offline

    17
    ReputationRep:
    Is it to base 3 or just log?

    I would do:

    log3[ (y^2)/(y + 4) ] = 2
    (y^2)/(y + 4) = 9

    And go from there.
    Offline

    14
    ReputationRep:
    (Original post by Regency)
    Has anyone have a clue how to solve this?

    calculate the value of y for which 2 log 3 y - log 3 (y+4) = 2

    Thanks in advance
    

2log(y) = log(y)^2 

log(y)^2-log(y+4) = log(y^2/y+4)



Anti log it So that y^2/y+4 = 3^2 

y^2 = 9y+36

y^2-9y-36 = 0 Factorise:  (y+3)(y-12)
    • Thread Starter
    Offline

    0
    ReputationRep:
    (Original post by StarvingAutist)
    Is it to base 3 or just log?

    I would do:

    log3[ (y^2)/(y + 4) ] = 2
    (y^2)/(y + 4) = 9

    And go from there.

    Yeah it was base 3 and thanks it helped
    • Thread Starter
    Offline

    0
    ReputationRep:
    (Original post by Jkizer)
    

2log(y) = log(y)^2 

log(y)^2-log(y+4) = log(y^2/y+4)



Anti log it So that y^2/y+4 = 3^2 

y^2 = 9y+36

y^2-9y-36 = 0 Factorise:  (y+3)(y-12)

    Thank you
    Offline

    17
    ReputationRep:
    (Original post by Regency)
    Yeah it was base 3 and thanks it helped
    No problem, you just have to use the log rules (guy above explained it better)
    • Thread Starter
    Offline

    0
    ReputationRep:
    (Original post by StarvingAutist)
    No problem, you just have to use the log rules (guy above explained it better)

    You both helped
    • Thread Starter
    Offline

    0
    ReputationRep:
    Hi sorry to bother you but could you help me with this question please:

    This question is taken from C2: mixed exercises booklet - EX6D

    A triangle OCD with
    OC=17cm
    OD=17cm
    CD=30cm
    The midpoint of CD is M. With centre M, a semicircular arc A1 is drawn on CD as diameter. With centre O and radius 17cm, a circular arc A2 is drawn from C to D. The shaded region R is bounded by the arcs A1 and A2. Find

    a) The area of triangle OCD

    b)The angle COD in radians

    c)Area of shaded region R

    Thanks in advance
 
 
 
Reply
Submit reply
Turn on thread page Beta
Updated: February 10, 2014
Poll
Are you going to a festival?
Help with your A-levels

All the essentials

The adventure begins mug

Student life: what to expect

What it's really like going to uni

Rosette

Essay expert

Learn to write like a pro with our ultimate essay guide.

Uni match

Uni match

Our tool will help you find the perfect course for you

Study planner

Create a study plan

Get your head around what you need to do and when with the study planner tool.

Study planner

Resources by subject

Everything from mind maps to class notes.

Hands typing

Degrees without fees

Discover more about degree-level apprenticeships.

A student doing homework

Study tips from A* students

Students who got top grades in their A-levels share their secrets

Study help links and info

Can you help? Study help unanswered threadsRules and posting guidelines

Groups associated with this forum:

View associated groups

The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE

Write a reply...
Reply
Hide
Reputation gems: You get these gems as you gain rep from other members for making good contributions and giving helpful advice.