• Best of luck to the class of 2024 for their HSC exams. You got this!
    Let us know your thoughts on the HSC exams here
  • YOU can help the next generation of students in the community!
    Share your trial papers and notes on our Notes & Resources page
MedVision ad

Qs in complex number (1 Viewer)

rheno

New Member
Joined
Nov 4, 2006
Messages
13
Gender
Female
HSC
2008
Solve:
cos^2 ax^2 +sin2ax + 1= 0


i'm just starting on complex number...can u help me solve this question, plz?
 
P

pLuvia

Guest
Use quadratic formula and it should yield something nice

After you use the formula and simplify you should get this
x=-sin2a+icosa
 
Last edited by a moderator:

rheno

New Member
Joined
Nov 4, 2006
Messages
13
Gender
Female
HSC
2008
i know that i should use quadratic formula, but i can not solve it......i'm really stuck ...but the answer is -tan a+- i
i dunno how to get the answer...can u plz show me???
 

Bank$

Member
Joined
Mar 13, 2006
Messages
150
Location
Parramatta
Gender
Male
HSC
2007
use the sub cos^2(ax) = 1-sin^2(ax) then make it into the form:

ax^2 + bx + c=0 (with the sub that x=sinax)

then find sinax with the formula:

minus b plus or minus sq. root of b squared minus 4 times "a" times "c" over 2a.

then do the 2k(pie) thing
 

Users Who Are Viewing This Thread (Users: 0, Guests: 1)

Top