To find b, what should you use?34SBSinc{bc Sin A CosB0 6 = 4 + 2 Zae cos( B)...

Find the cosine of the angle between a and b and make a sketch. (a) $\quad \mathbf{a}=\langle 1,-3\rangle, \mathbf{b}=\langle-1,2\rangle$ (b) $\mathbf{a}=\langle-1,-2\rangle, \mathbf{b}=\langle 6,0\rangle$ (c) $\quad \mathbf{a}=\langle 2,-1\rangle, \mathbf{b}=\langle-2,-4\rangle$ (d) $\mathbf{a}=\langle 4,-7\rangle, \mathbf{b}=\langle-8,10\rangle$

So we have problem number 26 and this will have been given Sign a quarter to four x 5 and Cosby equal to one by three and A and B both live and train in the interval zero comma five or two. So first quarter and in first point all the ratio will be positive. So cause a one minus science. Quite a. According to pentagon identity. So 1 -4 x five. Well it's quite So 25 -4 And there were 21 x five. Similarly here saying B will be equal to one minus cause a Squire B. And the route So 1 -1 x three square. Also nine x 3 nine min. 1 eight x 3 202 x three. We have signed A. We have signed baby of course we have Cosby. So question number eight we have to find sign A minus B. Sign A minus B. Which is same A. Because B minus because a send me So sign is for by five. of course be is one x 3 minus cost A. Is under printable by five And saying B is 202 x three. So this is four x 15 minus two. and the route 42 by 15 The 4 -2 Under Road 42 by 15. So this is the value for a sign A minus B. Similarly pardon me cost A plus B equal to because A cause me minus saying Sandy we have caused a equal to Okay this is ah this is on because they should have been They should have been 25 -16 9 x 25. That is three x 5. Okay three x 5. Sorry for this for about five signing Cosby because there's three by five, three by five mm this is 602, This is 602. Now course a. We have courses which is three x 5 Cosby, which is one x 3 and minus Sign a four x 5 and sign B Sign be we have to route to buy three, So this is three 8, 2 x 15. They should be the answer. Thank you.

Sine a equals water for you, it implies for you it was city. What? And fine. Because be he was 1/3. It implied sewing bee equals. Who's here? Over three in you Go to bye bye. Now we have kind of a new sign. A minus Bi sign a minus bi portal sign. We'll be minus for the air sign. What sign is? Well, don't want to buy you. And also being run over minus for the three over and signed B scale who were to be the women. So just as this is for over 15 minus six. Scared about what? So if we did to over 15 Pirmin were left red Tu minus three scared Do it. Is that require? Now we have to find but it Let's be Let's be a little more Cosby minus sign Sign The board is your If I and course B is one over my no sign is Or what about you? There is a sign be is tools work the bigger chance. And this is who you are. No. Five minus its who What 50 Which is the required

It is given sign a the goods number three and we'll be He was not one by also in there to battery imply ease because he would. It's here though five by three and B equals inactive and therefore implying signed Be the course skilled 15 by who and bye bye to do. But now we have to find the value off sign a plus B off sign The blessed the is a corporal sign was the yes signed the no we will substitute or whatever you over here we know that sign It is moreover, three and I will be isn't active on over less Audie is get off by 13 and sign Be scared off 15 No, we have been told this thing. So this is equal to negative to work well last scheduled off 75 What? But because different environments empty So this is a photo narrative to or plus scared of 7500 Internet by scared Ruto 30 over indistinct and butter in there One No work Well, no give to last five years City did the answer for sign Plus me No, we have to find off a minus bi No, because he may not be Corfu. What was we'll be last sign sign? Of course, it is scared off by or tree. And Cosby is like people know where what sign is worth. Three and a sign. Be scared of what? But this thing becomes five. The last school schedule. So this is the portal run over. Well, no use getting off last June. Scared? Which is the required artist or weekends in this for that as one. Know what? Well, nothing scared. Don't fly. Plus two, we can escape from the Penis. Get about five times three and we can take scheduled by equipment. So it is scared. I work well. Next day, one brush full scale.

Hello, we have another number 25 and this we need to find sign A plus B because they might be okay and given is sane a sequel to to buy three and Cause be equal to -1 x four and in the interval by went to Dubai, so this is in second quadrant, so if it is in second quarter in and we both had second quarter, so signing A should be positive, Cosby should be negative. Now we need to find the value of course because oh this should be negative Because it is in second quadrant and one science Choir according to what about an identity minus one minus To buy three old square minus 1 -4 x nine, so this is minus Under five x 3. Similarly here we were finding out Sign be since being in second quarter and so sign has to be positive, so plus one minus causes square B, so one minus -1 x four Whole Square, So 1 -1 x 16 Under 15 x four. We have all day, we have completed the required things. So let us get started saying A plus B which is sign a Cosby place cause a Sandy. So we have signed equal to two x 3 Into cost. Be aged under 15 x four. No minus on my phone given all day -1 x four class. Cause a -15 x three signed B Under Road 15 x four. So this is -2 x 12 75 90 503 x 12. So sign a plus B will be equal to -2 -503 by Okay. But be it Because a -1 of course A minus B which is equal to cause a Cosby. MS. Sign a Sandy because a Cosby is because it is uh -005 x three. Cosby Is -1 x four. This saying, is To buy three and signed B is UNDER 15 x four. So this will become minus under fire. I'm sorry, plus under fire because minus and mines were looking place under five plus two Under Rule 15 by for so they should be the answer. These are the answers. Thank you.