home *** CD-ROM | disk | FTP | other *** search
- 210
- à 7.3è The Ellipse
- äè Please use the square root property to find the x-inter-
- cepts of the given ellipse.
- #âë Find the x-intercepts of the ellipse, 4xì + 9yìï=ï36.
-
- #êêêë4xì + 9(0)ìï=ï36
- #êêêêêxìï= 9
- #êêêêê┌─
- #êêêë xï=ï± á9ï=ï± 3
- êêèThe x-intercepts are (3, 0) and (-3, 0).
- #éS An equation of the form, axì + byìï=ïc, is recognizable as an
- ellipse where a, b, and c are constants with the same sign.ïIn the
- #example 4xì + 9yìï=ï36, a = 4, b = 9, and c = 36.ïThis equation is
- recognizable as an ellipse, and a reasonably good graph can be found by
- plotting the intercepts and joining them with a smooth curve.ïThe x-
- intercepts are found by letting y equal 0 and solving for x.
-
- #êêê 4xì + 9(0)ìï=ï36
- #êêêêï4xìï=ï36
- #êêêêèxìï=ï9
- #êêêêê┌─
- #êêêë xï=ï± á9ï=ï± 3
- êêïThe x-intercepts are (3, 0) and (-3, 0).
- 1
-
- #êïFind the x-intercepts of the ellipse, 16xì + 9yìï=ï144.
-
-
- A)ï(3, 0)(-3, 0)èB)ï(6, 0)(-6, 0)èC)ï(4, 0)(-4, 0)èD)ïå
- #üêêè16xì + 9yìï=ï144
- #êêê16xì + 9(0)ìï=ï144
- #êêêê 16xìï=ï144
- #êêêêèxìï=ï9
- #êêêêê┌─
- #êêêë xï=ï± á9ï=ï± 3
- êêè The x-intercepts are (3, 0) and (-3, 0).
- Ç A
- 2
-
- #êïFind the x-intercepts of the ellipse, 25xì + 16yìï=ï400.
-
-
- A)ï(5, 0)(-5, 0)èB)ï(20, 0)(-20, 0)èC)ï(4, 0)(-4, 0)èD)ïå
- #üêêï25xì + 16yìï=ï400
- #êêë 25xì + 16(0)ìï=ï400
- #êêêê 25xìï=ï400
- #êêêêèxìï=ï16
- #êêêêê┌──
- #êêêë xï=ï± á16ï=ï± 4
- êêïThe x-intercepts are (4, 0) and (-4, 0).
- Ç C
- 3
-
- #êïFind the x-intercepts of the ellipse, 4xì + 49yìï=ï196.
-
-
- A)ï(2, 0)(-2, 0)è B)ï(8, 0)(-8, 0)è C)ï(7, 0)(-7, 0)èD)ïå
- #üêêè4xì + 49yìï=ï196
- #êêê4xì + 49(0)ìï=ï196
- #êêêêï4xìï=ï196
- #êêêêèxìï=ï49
- #êêêêê┌──
- #êêêë xï=ï± á49ï=ï± 7
- êêèThe x-intercepts are (7, 0) and (-7, 0).
- Ç C
- 4
-
- #êïFind the x-intercepts of the ellipse, 4xì + 16yìï=ï64.
-
-
- èA)ï(4, 0)(-4, 0)èB)ï(7, 0)(-7, 0)èC)ï(2, 0)(-2, 0)èD)ïå
- #üêêè4xì + 16yìï=ï64
- #êêê4xì + 16(0)ìï=ï64
- #êêêêï4xìï=ï64
- #êêêêèxìï=ï16
- #êêêêê┌──
- #êêêë xï=ï± á16ï=ï± 4
- êêèThe x-intercepts are (4, 0) and (-4, 0).
- Ç A
-
- # 5ëFind the x-intercepts of the ellipse, 7xì + 5yìï=ï35.
-
- #êê┌──ê ┌──êêê ┌─ê ┌─
- #êïA)ï(á35, 0), (-á35, 0)êë B)ï(á5, 0), (-á5, 0)
- #êê┌─ê ┌─
- #êïC)ï(á7, 0), (-á7, 0)êê D)ïå
-
- #üêêè 7xì + 5yìï=ï35
- #êêê 7xì + 5(0)ìï=ï35
- #êêêêï7xìï=ï35
- #êêêêèxìï=ï5
- #êêêêêë┌─
- #êêêêè xï=ï± á5
- #êêêêêè┌─êè ┌─
- #êêïThe x-intercepts are (á5, 0) and (-á5, 0).
-
- Ç B
- äè Please use the square root property to find the y-inter-
- cepts of the given ellipse.
- #âëFind the y-intercepts of the ellipse, 4xì + 9yìï=ï36.
-
- #è Let xï=ï0, then 4(0)ì + 9yìï=ï36
- #êêêêèyìï=ï4
- #êêêêê ┌─
- #êêêêyï=ï± á4ï=ï± 2
- êêè The y-intercepts are (0,2) and (0,-2).
- #éS The y-intercepts of the ellipse, 4xì + 9yìï=ï36, are found by
- letting x equal zero and solving for y.
-
- #êêê 4(0)ì + 9yìï=ï36
- #êêêêï9yìï=ï36
- #êêêêèyìï=ï4
- #êêêêê┌─
- #êêêë yï=ï± á4ï=ï± 2
- êê The y-intercepts are (0, 2) and (0, -2).
- 6
-
- #ê Find the y-intercepts of the ellipse, 16xì + 9yìï=ï144.
-
-
- ëA) (0, 3)(0, -3)èB) (0, 4)(0, -4)è C) (0, 6)(0, -6)è D) å
- #üêêè16xì + 9yìï=ï144
- #êêê16(0)ì + 9yìï=ï144
- #êêêêï9yìï=ï144
- #êêêêèyìï=ï16
- #êêêêê┌──
- #êêêë yï=ï± á16ï=ï± 4
- êêïThe y-intercepts are (0, 4) and (0, -4).
- Ç B
- 7
-
- #ê Find the y-intercepts of the ellipse, 25xì + 16yìï=ï400.
-
-
- èA) (0, 5)(0, -5)èB) (0, 4)(0, -4)è C) (0, 20)(0, -20)è D) å
- #üêêï25xì + 16yìï=ï400
- #êêë 25(0)ì + 16yìï=ï400
- #êêêê 16yìï=ï400
- #êêêêèyìï=ï25
- #êêêêê┌──
- #êêêë yï=ï± á25ï=ï± 5
- êêïThe y-intercepts are (0, 5) and (0, -5).
- Ç A
- 8
-
- #ê Find the y-intercepts of the ellipse, 4xì + 49yìï=ï196.
-
-
- ïA) (0, 2)(0, -2)ëB) (0, 7)(0, -7)è C) (0, 8)(0, -8)èD)ïå
- #üêêè4xì + 49yìï=ï196
- #êêê4(0)ì + 49yìï=ï196
- #êêêê 49yìï=ï196
- #êêêêèyìï=ï4
- #êêêêê┌─
- #êêêë yï=ï± á4ï=ï± 2
- êêïThe y-intercepts are (0, 2) and (0, -2).
- Ç A
- 9
-
- #êèFind the y-intercepts of the ellipse, 4xì + 16yìï=ï64.
-
-
- è A) (0, 4)(0, -4)è B) (0, 7)(0, -7)è C) (0, 2)(0, -2)è D) å
- #üêêè4xì + 16yìï=ï64
- #êêê4(0)ì + 16yìï=ï64
- #êêêê 16yìï=ï64
- #êêêêèyìï=ï4
- #êêêêê┌─
- #êêêë yï=ï± á4ï=ï± 2
- êêïThe y-intercepts are (0, 2) and (0, -2).
- Ç C
-
- # 10èFind the y-intercepts of the ellipse, 7xì + 5yìï=ï35.
-
- #êê ┌──êï┌──êêê ┌─êï┌─
- #ê A) (0, á35 ), (0, -á35 )êë B) (0, á5 ), (0, -á5 )
- #êê ┌─êï┌─
- #ê C) (0, á7 ), (0, -á7 )êê D) å
-
- #üêêè 7xì + 5yìï=ï35
- #êêê 7(0)ì + 5yìï=ï35
- #êêêêï5yìï=ï35
- #êêêêèyìï=ï7
- #êêêêêë┌─
- #êêêêè yï=ï± á7
- #êêêêêë┌─êë┌─
- #êê The y-intercepts are (0, á7 ) and (0, -á7 ).
-
- Ç C
- # 11ê Graph the ellipse 16xì + 9yìï=ï144.
- @fig7301.bmp,28,225
- @fig7302.bmp,234,225
- @fig7303.bmp,450,225
- #üêêGraph the ellipse 16xì + 9yìï=ï144.
-
- êêêêê x interceptsï(3,0)(-3,0)
- êêêêê y interceptsï(0,4)(0,-4)
- @fig7307.bmp,80,850
- Ç A
- # 12ê Graph the ellipse 4xì + 9yìï=ï36.
- @fig7304.bmp,28,225
- @fig7305.bmp,234,225
- @fig7306.bmp,450,225
- #üêê Graph the ellipse 4xì + 9yìï=ï36.
-
- êêêêê x-interceptsï(3,0)(-3,0)
- êêêêê y-interceptsï(0,2)(0,-2)
- @fig7308.bmp,80,850
- Ç B
-
-