All right in this question 58 we're going to try to find a solution three problems and then we or even know that T is equal to que times l warm over are one to the part of four plus l two over our two to borrow for so we know this expression. We can also produce the following expressions using the angle theta and also using at trigonometry skills from the figure by looking at the figure. So basically, l warm is gonna vehicle to al for minus C b. And from there, CB the length of CB is gonna be equal to l three times court engine data. And if I substitute there, l one So basically, if I substance the length of CB into the first equation so the L one is gonna be cooked to l four minus l three times contingency data it. And then we also know that l two is also equal to l three times cause second satar. So if I get all these things and try to put them back together into the original formula or original equation, we're going to get that tea is gonna be equal to okay. times l four minus l three times contingency data over our one to the father of four plus l three times Corsican theater over or two to the plot before. So which is the thing that we need to verify for this problem, for part or it important be we're gonna try to minimize this expression. So if I try to minimize expression, I need to focus on poor beats. I need to focus arm t prime Seita. And when it set, this equals you. So which means we're gonna find the first derivative of this expression with respect data and Saturday called zero and tried to solve the equation. Port data. All right, so let's do that. So, basically, Kate, times que times l three times for second square theta over are 12 department for so basically Corsican square theta is the the first derivative of potential data. That's where it's coming from and minus minus. L three times contingent Seda times cause sequinned data and divided by r two to the part of for equals zero. And this expression is the derivative off contingents. Uh, so the derivative, of course. Sequent Satar. All right, so, uh, if I solved. If I divide inside by key, this is gonna be able to just so que times. So since both of the terms are having the same common term, which is l of three. So if I take if I factor out of k times l of three. So we're going to get that, uh, cause second squared theta over our one to the problem for minus court. Ancient data times for second data over our two to depart for And this is gonna be called zero. And if I divide inside by k times l three. So this expression will be equal to cause seconds square Seita over our 12 bar before and minus contingent Seder times Coursey consider over our two department for its gonna vehicle zero. All right. And they find love, uh, this thing the second term over to another side. So we get that course Second squad data over our wants. The part of four will be equal to contain Geant Seda times consequent Saito over our two department for So let me is different color because we need We have some things to simplify. So it is gonna be cool. Just course second Corsican data and it's going to be gone. So basically, this expression is gonna be equal to cause second, sir Course sequined Fada over or want to A part of four will be Connecticut Angels data over our two appointment for and finally the finally are to, uh this expression is gonna be called after to some necessary in trigonometry and algebraic simplification that we're going to get this cosign theta is gonna be equal to R two over our one to the power for Okay, so we kind of we kind of get the solution in terms off pie like that's kind of implicit, but its coastline physical are two over. Our one is equal before that divide to department for or import see good import. See, So as showing the figure are too is smaller than our one and which is equals R two physical true, zero point 85 times are according to the problem. So basically, course science later. Remember this expression call sign theater was equal to are two over our one to the power for so basic the instead of putting are off to are too. If I put as your 0.85 times are Once we're going to get this consign, Fada is gonna be equal to 0.85 times are one over are one and to depart before. So this are ones are going to be gone. And from their call sign, Beta is gonna be equal. True, just 0.85 to department four. So once we calculate this expression on the right, the coast science data is gonna be a culture just 0.5 to 2 using our calculators. 006 Okay. And then from there, if I used the inverse coastline function, inverse trigonometry function later is gonna be equal to 1.2 15 plus two ply. And so, basically, it's gonna repeat for everything on the 60 degree. That's the answer for part C.